diff mbox

extcon-next regression ?

Message ID 20140423182851.GT9593@saruman.home
State New
Headers show

Commit Message

Felipe Balbi April 23, 2014, 6:28 p.m. UTC
Hi,

On Wed, Apr 23, 2014 at 12:20:52PM -0500, Felipe Balbi wrote:
> > I've been testing extcon-next to make sure USB3 on OMAP5 will work out
> > of the box but I see a regression when I merge your tree on top of
> > v3.15-rc2 + Tony's DT fixes.
> > 
> > Here's what I see (trimmed):
> > 
> > [    1.805870] palmas 0-0048: Muxing GPIO 2, PWM 0, LED 0
> > [    1.812516] ------------[ cut here ]------------
> > [    1.817387] WARNING: CPU: 0 PID: 6 at include/linux/kref.h:47 kobject_get+0x64/0x78()
> > [    1.817691]  mmcblk0boot1: unknown partition table
> > [    1.830601] Modules linked in:
> > [    1.833827] CPU: 0 PID: 6 Comm: kworker/u4:0 Tainted: G        W     3.15.0-rc2-00041-g3019b77 #308
> > [    1.843333] Workqueue: deferwq deferred_probe_work_func
> > [    1.848728]  mmcblk0boot0: unknown partition table
> > [    1.853928] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
> > [    1.862086] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
> > [    1.869667] [<c05426b4>] (dump_stack) from [<c0040928>] (warn_slowpath_common+0x6c/0x90)
> > [    1.878181] [<c0040928>] (warn_slowpath_common) from [<c00409e8>] (warn_slowpath_null+0x1c/0x24)
> > [    1.887421] [<c00409e8>] (warn_slowpath_null) from [<c02d50c4>] (kobject_get+0x64/0x78)
> > [    1.895837] [<c02d50c4>] (kobject_get) from [<c0350188>] (device_add+0x18/0x520)
> > [    1.903629] [<c0350188>] (device_add) from [<c0462a5c>] (extcon_dev_register+0x48/0x104)
> > [    1.912145] [<c0462a5c>] (extcon_dev_register) from [<c0462b44>] (devm_extcon_dev_register+0x2c/0x68)
> > [    1.921847] [<c0462b44>] (devm_extcon_dev_register) from [<c04630c0>] (palmas_usb_probe+0x110/0x304)
> > [    1.931453] [<c04630c0>] (palmas_usb_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> > [    1.940333] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> > [    1.949664] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> > [    1.958634] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> > [    1.967003] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> > [    1.975387] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> > [    1.983678] [<c0350590>] (device_add) from [<c045a310>] (of_platform_device_create_pdata+0x6c/0x8c)
> > [    1.993155] [<c045a310>] (of_platform_device_create_pdata) from [<c045a418>] (of_platform_bus_create+0xdc/0x168)
> > [    2.003818] [<c045a418>] (of_platform_bus_create) from [<c045a5cc>] (of_platform_populate+0x5c/0xa0)
> > [    2.013399] [<c045a5cc>] (of_platform_populate) from [<c0373c78>] (palmas_i2c_probe+0x30c/0x584)
> > [    2.022606] [<c0373c78>] (palmas_i2c_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> > [    2.031722] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> > [    2.040715] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> > [    2.049098] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> > [    2.057482] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> > [    2.065774] [<c0350590>] (device_add) from [<c0424020>] (i2c_new_device+0x12c/0x18c)
> > [    2.073885] [<c0424020>] (i2c_new_device) from [<c0424980>] (i2c_register_adapter+0x278/0x498)
> > [    2.082903] [<c0424980>] (i2c_register_adapter) from [<c04275c0>] (omap_i2c_probe+0x4a4/0x6d0)
> > [    2.091925] [<c04275c0>] (omap_i2c_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> > [    2.100582] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> > [    2.109883] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> > [    2.118823] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> > [    2.127194] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> > [    2.135584] [<c035206c>] (bus_probe_device) from [<c03524ac>] (deferred_probe_work_func+0x64/0x94)
> > [    2.144975] [<c03524ac>] (deferred_probe_work_func) from [<c0058c70>] (process_one_work+0x1ac/0x4cc)
> > [    2.154545] [<c0058c70>] (process_one_work) from [<c0059b10>] (worker_thread+0x114/0x3b4)
> > [    2.163119] [<c0059b10>] (worker_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
> > [    2.170695] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
> > [    2.178259] ---[ end trace 3006de6450234d28 ]---
> > [    2.183081] kobject 'palmas_usb' (eca58c38): tried to add an uninitialized object, something is seriously wrong.
> > [    2.193731] CPU: 0 PID: 6 Comm: kworker/u4:0 Tainted: G        W     3.15.0-rc2-00041-g3019b77 #308
> > [    2.203201] Workqueue: deferwq deferred_probe_work_func
> > [    2.208687] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
> > [    2.216789] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
> > [    2.224357] [<c05426b4>] (dump_stack) from [<c02d5c28>] (kobject_add+0x88/0x98)
> > [    2.232014] [<c02d5c28>] (kobject_add) from [<c0350250>] (device_add+0xe0/0x520)
> > [    2.239758] [<c0350250>] (device_add) from [<c0462a5c>] (extcon_dev_register+0x48/0x104)
> > [    2.248235] [<c0462a5c>] (extcon_dev_register) from [<c0462b44>] (devm_extcon_dev_register+0x2c/0x68)
> > [    2.257901] [<c0462b44>] (devm_extcon_dev_register) from [<c04630c0>] (palmas_usb_probe+0x110/0x304)
> > [    2.267467] [<c04630c0>] (palmas_usb_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> > [    2.276298] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> > [    2.285591] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> > [    2.294520] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> > [    2.302905] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> > [    2.311286] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> > [    2.319583] [<c0350590>] (device_add) from [<c045a310>] (of_platform_device_create_pdata+0x6c/0x8c)
> > [    2.329063] [<c045a310>] (of_platform_device_create_pdata) from [<c045a418>] (of_platform_bus_create+0xdc/0x168)
> > [    2.339725] [<c045a418>] (of_platform_bus_create) from [<c045a5cc>] (of_platform_populate+0x5c/0xa0)
> > [    2.349296] [<c045a5cc>] (of_platform_populate) from [<c0373c78>] (palmas_i2c_probe+0x30c/0x584)
> > [    2.358496] [<c0373c78>] (palmas_i2c_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> > [    2.367609] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> > [    2.376523] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> > [    2.384914] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> > [    2.393301] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> > [    2.401601] [<c0350590>] (device_add) from [<c0424020>] (i2c_new_device+0x12c/0x18c)
> > [    2.409707] [<c0424020>] (i2c_new_device) from [<c0424980>] (i2c_register_adapter+0x278/0x498)
> > [    2.418727] [<c0424980>] (i2c_register_adapter) from [<c04275c0>] (omap_i2c_probe+0x4a4/0x6d0)
> > [    2.427741] [<c04275c0>] (omap_i2c_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> > [    2.436382] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> > [    2.445680] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> > [    2.454613] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> > [    2.463001] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> > [    2.471385] [<c035206c>] (bus_probe_device) from [<c03524ac>] (deferred_probe_work_func+0x64/0x94)
> > [    2.480772] [<c03524ac>] (deferred_probe_work_func) from [<c0058c70>] (process_one_work+0x1ac/0x4cc)
> > [    2.490339] [<c0058c70>] (process_one_work) from [<c0059b10>] (worker_thread+0x114/0x3b4)
> > [    2.498906] [<c0059b10>] (worker_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
> > [    2.506460] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
> > [    2.514023] ------------[ cut here ]------------
> > [    2.518870] WARNING: CPU: 0 PID: 6 at lib/kobject.c:670 kobject_put+0x80/0x90()
> > [    2.526514] kobject: 'palmas_usb' (eca58c38): is not initialized, yet kobject_put() is being called.
> > [    2.536076] Modules linked in:
> > [    2.539287] CPU: 0 PID: 6 Comm: kworker/u4:0 Tainted: G        W     3.15.0-rc2-00041-g3019b77 #308
> > [    2.548753] Workqueue: deferwq deferred_probe_work_func
> > [    2.554223] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
> > [    2.562341] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
> > [    2.569911] [<c05426b4>] (dump_stack) from [<c0040928>] (warn_slowpath_common+0x6c/0x90)
> > [    2.578391] [<c0040928>] (warn_slowpath_common) from [<c004097c>] (warn_slowpath_fmt+0x30/0x40)
> > [    2.587502] [<c004097c>] (warn_slowpath_fmt) from [<c02d5158>] (kobject_put+0x80/0x90)
> > [    2.595780] [<c02d5158>] (kobject_put) from [<c03502fc>] (device_add+0x18c/0x520)
> > [    2.603623] [<c03502fc>] (device_add) from [<c0462a5c>] (extcon_dev_register+0x48/0x104)
> > [    2.612103] [<c0462a5c>] (extcon_dev_register) from [<c0462b44>] (devm_extcon_dev_register+0x2c/0x68)
> > [    2.621762] [<c0462b44>] (devm_extcon_dev_register) from [<c04630c0>] (palmas_usb_probe+0x110/0x304)
> > [    2.631321] [<c04630c0>] (palmas_usb_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> > [    2.640161] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> > [    2.649447] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> > [    2.658386] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> > [    2.666757] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> > [    2.675144] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> > [    2.683441] [<c0350590>] (device_add) from [<c045a310>] (of_platform_device_create_pdata+0x6c/0x8c)
> > [    2.692921] [<c045a310>] (of_platform_device_create_pdata) from [<c045a418>] (of_platform_bus_create+0xdc/0x168)
> > [    2.703575] [<c045a418>] (of_platform_bus_create) from [<c045a5cc>] (of_platform_populate+0x5c/0xa0)
> > [    2.713139] [<c045a5cc>] (of_platform_populate) from [<c0373c78>] (palmas_i2c_probe+0x30c/0x584)
> > [    2.722341] [<c0373c78>] (palmas_i2c_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> > [    2.731457] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> > [    2.740380] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> > [    2.748764] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> > [    2.757135] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> > [    2.765429] [<c0350590>] (device_add) from [<c0424020>] (i2c_new_device+0x12c/0x18c)
> > [    2.773549] [<c0424020>] (i2c_new_device) from [<c0424980>] (i2c_register_adapter+0x278/0x498)
> > [    2.782576] [<c0424980>] (i2c_register_adapter) from [<c04275c0>] (omap_i2c_probe+0x4a4/0x6d0)
> > [    2.791597] [<c04275c0>] (omap_i2c_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> > [    2.800261] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> > [    2.809560] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> > [    2.818489] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> > [    2.826865] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> > [    2.835253] [<c035206c>] (bus_probe_device) from [<c03524ac>] (deferred_probe_work_func+0x64/0x94)
> > [    2.844637] [<c03524ac>] (deferred_probe_work_func) from [<c0058c70>] (process_one_work+0x1ac/0x4cc)
> > [    2.854205] [<c0058c70>] (process_one_work) from [<c0059b10>] (worker_thread+0x114/0x3b4)
> > [    2.862778] [<c0059b10>] (worker_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
> > [    2.870349] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
> > [    2.877911] ---[ end trace 3006de6450234d29 ]---
> > [    2.882734] ------------[ cut here ]------------
> > [    2.887573] WARNING: CPU: 0 PID: 6 at lib/kobject.c:670 kobject_put+0x80/0x90()
> > [    2.895209] kobject: 'palmas_usb' (eca58c38): is not initialized, yet kobject_put() is being called.
> > [    2.904765] Modules linked in:
> > [    2.907971] CPU: 0 PID: 6 Comm: kworker/u4:0 Tainted: G        W     3.15.0-rc2-00041-g3019b77 #308
> > [    2.917447] Workqueue: deferwq deferred_probe_work_func
> > [    2.922924] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
> > [    2.931033] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
> > [    2.938606] [<c05426b4>] (dump_stack) from [<c0040928>] (warn_slowpath_common+0x6c/0x90)
> > [    2.947069] [<c0040928>] (warn_slowpath_common) from [<c004097c>] (warn_slowpath_fmt+0x30/0x40)
> > [    2.956187] [<c004097c>] (warn_slowpath_fmt) from [<c02d5158>] (kobject_put+0x80/0x90)
> > [    2.964483] [<c02d5158>] (kobject_put) from [<c0462abc>] (extcon_dev_register+0xa8/0x104)
> > [    2.973053] [<c0462abc>] (extcon_dev_register) from [<c0462b44>] (devm_extcon_dev_register+0x2c/0x68)
> > [    2.982718] [<c0462b44>] (devm_extcon_dev_register) from [<c04630c0>] (palmas_usb_probe+0x110/0x304)
> > [    2.992285] [<c04630c0>] (palmas_usb_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> > [    3.001124] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> > [    3.010423] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> > [    3.019358] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> > [    3.027746] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> > [    3.036121] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> > [    3.044418] [<c0350590>] (device_add) from [<c045a310>] (of_platform_device_create_pdata+0x6c/0x8c)
> > [    3.053893] [<c045a310>] (of_platform_device_create_pdata) from [<c045a418>] (of_platform_bus_create+0xdc/0x168)
> > [    3.064550] [<c045a418>] (of_platform_bus_create) from [<c045a5cc>] (of_platform_populate+0x5c/0xa0)
> > [    3.074124] [<c045a5cc>] (of_platform_populate) from [<c0373c78>] (palmas_i2c_probe+0x30c/0x584)
> > [    3.083338] [<c0373c78>] (palmas_i2c_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> > [    3.092447] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> > [    3.101381] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> > [    3.109767] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> > [    3.118147] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> > [    3.126432] [<c0350590>] (device_add) from [<c0424020>] (i2c_new_device+0x12c/0x18c)
> > [    3.134547] [<c0424020>] (i2c_new_device) from [<c0424980>] (i2c_register_adapter+0x278/0x498)
> > [    3.143569] [<c0424980>] (i2c_register_adapter) from [<c04275c0>] (omap_i2c_probe+0x4a4/0x6d0)
> > [    3.152593] [<c04275c0>] (omap_i2c_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> > [    3.161249] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> > [    3.170537] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> > [    3.179472] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> > [    3.187854] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> > [    3.196222] [<c035206c>] (bus_probe_device) from [<c03524ac>] (deferred_probe_work_func+0x64/0x94)
> > [    3.205611] [<c03524ac>] (deferred_probe_work_func) from [<c0058c70>] (process_one_work+0x1ac/0x4cc)
> > [    3.215174] [<c0058c70>] (process_one_work) from [<c0059b10>] (worker_thread+0x114/0x3b4)
> > [    3.223739] [<c0059b10>] (worker_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
> > [    3.231313] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
> > [    3.238883] ---[ end trace 3006de6450234d2a ]---
> > [    3.243711] palmas-usb palmas_usb.7: failed to register extcon device
> > [    3.250493] palmas-usb: probe of palmas_usb.7 failed with error -22
> > 
> > Any ideas ??
> 
> bisected down to:
> 
> commit 854b85057cc6b90a326b731174b6c6dbbf34222a
> Author: Chanwoo Choi <cw00.choi@samsung.com>
> Date:   Mon Apr 21 19:46:51 2014 +0900
> 
>     extcon: Add extcon_dev_allocate/free() to control the memory of extcon device
>     
>     This patch add APIs to control the extcon device on extcon provider driver.
>     The extcon_dev_allocate() allocates the memory of extcon device and initializes
>     supported cables. And then extcon_dev_free() decrement the reference of the
>     device of extcon device and free the memory of the extcon device. This APIs
>     must need to implement devm_extcon_dev_allocate()/free() APIs.
>     
>     Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
> 
> diff --git a/drivers/extcon/extcon-class.c b/drivers/extcon/extcon-class.c
> index f6df689..3e485bc 100644
> --- a/drivers/extcon/extcon-class.c
> +++ b/drivers/extcon/extcon-class.c
> @@ -558,6 +558,9 @@ static int create_extcon_class(void)
>  
>  static void extcon_dev_release(struct device *dev)
>  {
> +	struct extcon_dev *edev = dev_to_extcon_dev(dev);
> +
> +	kfree(edev);
>  }
>  
>  static const char *muex_name = "mutually_exclusive";
> @@ -576,7 +579,7 @@ static void dummy_sysfs_dev_release(struct device *dev)
>   */
>  int extcon_dev_register(struct extcon_dev *edev)
>  {
> -	int ret, index = 0;
> +	int ret;
>  
>  	if (!extcon_class) {
>  		ret = create_extcon_class();
> @@ -584,80 +587,150 @@ int extcon_dev_register(struct extcon_dev *edev)
>  			return ret;
>  	}
>  
> -	if (edev->supported_cable) {
> -		/* Get size of array */
> -		for (index = 0; edev->supported_cable[index]; index++)
> -			;
> -		edev->max_supported = index;
> -	} else {
> -		edev->max_supported = 0;
> +	edev->name = edev->name ? edev->name : dev_name(edev->dev.parent);
> +	if (IS_ERR_OR_NULL(edev->name)) {
> +		dev_err(&edev->dev, "extcon device name is null\n");
> +		return -EINVAL;
>  	}
> +	dev_set_name(&edev->dev, "%s", edev->name);
>  
> -	if (index > SUPPORTED_CABLE_MAX) {
> -		dev_err(&edev->dev, "extcon: maximum number of supported cables exceeded.\n");
> -		return -EINVAL;
> +	ret = device_add(&edev->dev);
> +	if (ret) {
> +		put_device(&edev->dev);
> +		return ret;
>  	}
> +#if defined(CONFIG_ANDROID)
> +	if (switch_class)
> +		ret = class_compat_create_link(switch_class, &edev->dev, NULL);
> +#endif /* CONFIG_ANDROID */
>  
> -	edev->dev.class = extcon_class;
> -	edev->dev.release = extcon_dev_release;
> +	RAW_INIT_NOTIFIER_HEAD(&edev->nh);
>  
> -	edev->name = edev->name ? edev->name : dev_name(edev->dev.parent);
> -	if (IS_ERR_OR_NULL(edev->name)) {
> -		dev_err(&edev->dev,
> -			"extcon device name is null\n");
> -		return -EINVAL;
> +	dev_set_drvdata(&edev->dev, edev);
> +	edev->state = 0;
> +
> +	mutex_lock(&extcon_dev_list_lock);
> +	list_add(&edev->entry, &extcon_dev_list);
> +	mutex_unlock(&extcon_dev_list_lock);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(extcon_dev_register);
> +
> +/**
> + * extcon_dev_unregister() - Unregister the extcon device.
> + * @edev:	the extcon device instance to be unregistered.
> + */
> +void extcon_dev_unregister(struct extcon_dev *edev)
> +{
> +	mutex_lock(&extcon_dev_list_lock);
> +	list_del(&edev->entry);
> +	mutex_unlock(&extcon_dev_list_lock);
> +
> +	if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
> +		dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
> +				dev_name(&edev->dev));
> +		return;
>  	}
> -	dev_set_name(&edev->dev, "%s", edev->name);
>  
> -	if (edev->max_supported) {
> -		char buf[10];
> -		char *str;
> -		struct extcon_cable *cable;
> +	device_unregister(&edev->dev);
>  
> -		edev->cables = kzalloc(sizeof(struct extcon_cable) *
> -				       edev->max_supported, GFP_KERNEL);
> -		if (!edev->cables) {
> +#if defined(CONFIG_ANDROID)
> +	if (switch_class)
> +		class_compat_remove_link(switch_class, &edev->dev, NULL);
> +#endif
> +}
> +EXPORT_SYMBOL_GPL(extcon_dev_unregister);
> +
> +/*
> + * extcon_dev_allocate() - Allocate the memory of extcon device.
> + * @supported_cable:	Array of supported cable names ending with NULL.
> + *			If supported_cable is NULL, cable name related APIs
> + *			are disabled.
> + *
> + * This function allocates the memory for extcon device without allocating
> + * memory in each extcon provider driver and initialize default setting for
> + * extcon device.
> + *
> + * Return the pointer of extcon device if success or ERR_PTR(err) if fail
> + */
> +struct extcon_dev *extcon_dev_allocate(const char **supported_cable)
> +{
> +	struct extcon_dev *edev;
> +	int index, ret, count = 0;
> +
> +	edev = kzalloc(sizeof(*edev), GFP_KERNEL);
> +	if (!edev) {
> +		pr_err("Failed to allocate the memory for extcon device\n");
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	edev->max_supported = 0;
> +	edev->supported_cable = supported_cable;
> +	if (edev->supported_cable) {
> +		for (count = 0; edev->supported_cable[count]; count++)
> +			;
> +		edev->max_supported = count;
> +		if (count > SUPPORTED_CABLE_MAX) {
> +			pr_err("Exceed max number of supported cables\n");
>  			ret = -ENOMEM;
> -			goto err_sysfs_alloc;
> +			goto err;
>  		}
> -		for (index = 0; index < edev->max_supported; index++) {
> -			cable = &edev->cables[index];
> +	}
>  
> -			snprintf(buf, 10, "cable.%d", index);
> -			str = kzalloc(sizeof(char) * (strlen(buf) + 1),
> -				      GFP_KERNEL);
> -			if (!str) {
> -				for (index--; index >= 0; index--) {
> -					cable = &edev->cables[index];
> -					kfree(cable->attr_g.name);
> -				}
> -				ret = -ENOMEM;
> +	edev->dev.class = extcon_class;
> +	edev->dev.release = extcon_dev_release;
> +	device_initialize(&edev->dev);
> +	spin_lock_init(&edev->lock);
> +
> +	if (!edev->max_supported)
> +		return 0;
> +
> +	edev->cables = kzalloc(sizeof(struct extcon_cable) *
> +			       edev->max_supported, GFP_KERNEL);
> +	if (!edev->cables) {
> +		ret = -ENOMEM;
> +		goto err;
> +	}
>  
> -				goto err_alloc_cables;
> +	for (index = 0; index < edev->max_supported; index++) {
> +		struct extcon_cable *cable = &edev->cables[index];
> +		char buf[10];
> +		char *str;
> +
> +		snprintf(buf, 10, "cable.%d", index);
> +		str = kzalloc(sizeof(char) * (strlen(buf) + 1),
> +			      GFP_KERNEL);
> +		if (!str) {
> +			for (index--; index >= 0; index--) {
> +				cable = &edev->cables[index];
> +				kfree(cable->attr_g.name);
>  			}
> -			strcpy(str, buf);
> -
> -			cable->edev = edev;
> -			cable->cable_index = index;
> -			cable->attrs[0] = &cable->attr_name.attr;
> -			cable->attrs[1] = &cable->attr_state.attr;
> -			cable->attrs[2] = NULL;
> -			cable->attr_g.name = str;
> -			cable->attr_g.attrs = cable->attrs;
> -
> -			sysfs_attr_init(&cable->attr_name.attr);
> -			cable->attr_name.attr.name = "name";
> -			cable->attr_name.attr.mode = 0444;
> -			cable->attr_name.show = cable_name_show;
> -
> -			sysfs_attr_init(&cable->attr_state.attr);
> -			cable->attr_state.attr.name = "state";
> -			cable->attr_state.attr.mode = 0444;
> -			cable->attr_state.show = cable_state_show;
> +			ret = -ENOMEM;
> +			goto err_alloc_cables;
>  		}
> +		strcpy(str, buf);
> +
> +		cable->edev = edev;
> +		cable->cable_index = index;
> +		cable->attrs[0] = &cable->attr_name.attr;
> +		cable->attrs[1] = &cable->attr_state.attr;
> +		cable->attrs[2] = NULL;
> +		cable->attr_g.name = str;
> +		cable->attr_g.attrs = cable->attrs;
> +
> +		sysfs_attr_init(&cable->attr_name.attr);
> +		cable->attr_name.attr.name = "name";
> +		cable->attr_name.attr.mode = 0444;
> +		cable->attr_name.show = cable_name_show;
> +
> +		sysfs_attr_init(&cable->attr_state.attr);
> +		cable->attr_state.attr.name = "state";
> +		cable->attr_state.attr.mode = 0444;
> +		cable->attr_state.show = cable_state_show;
>  	}
>  
> -	if (edev->max_supported && edev->mutually_exclusive) {
> +	if (edev->mutually_exclusive) {
>  		char buf[80];
>  		char *name;
>  
> @@ -703,59 +776,32 @@ int extcon_dev_register(struct extcon_dev *edev)
>  		}
>  		edev->attr_g_muex.name = muex_name;
>  		edev->attr_g_muex.attrs = edev->attrs_muex;
> -
>  	}
>  
> -	if (edev->max_supported) {
> -		edev->extcon_dev_type.groups =
> -			kzalloc(sizeof(struct attribute_group *) *
> -				(edev->max_supported + 2), GFP_KERNEL);
> -		if (!edev->extcon_dev_type.groups) {
> -			ret = -ENOMEM;
> -			goto err_alloc_groups;
> -		}
> -
> -		edev->extcon_dev_type.name = dev_name(&edev->dev);
> -		edev->extcon_dev_type.release = dummy_sysfs_dev_release;
> -
> -		for (index = 0; index < edev->max_supported; index++)
> -			edev->extcon_dev_type.groups[index] =
> -				&edev->cables[index].attr_g;
> -		if (edev->mutually_exclusive)
> -			edev->extcon_dev_type.groups[index] =
> -				&edev->attr_g_muex;
> -
> -		edev->dev.type = &edev->extcon_dev_type;
> +	edev->extcon_dev_type.groups =
> +		kzalloc(sizeof(struct attribute_group *) *
> +			(edev->max_supported + 2), GFP_KERNEL);
> +	if (!edev->extcon_dev_type.groups) {
> +		ret = -ENOMEM;
> +		goto err_alloc_groups;
>  	}
>  
> -	ret = device_register(&edev->dev);
> -	if (ret) {
> -		put_device(&edev->dev);
> -		goto err_dev;
> -	}
> -#if defined(CONFIG_ANDROID)
> -	if (switch_class)
> -		ret = class_compat_create_link(switch_class, &edev->dev, NULL);
> -#endif /* CONFIG_ANDROID */
> -
> -	spin_lock_init(&edev->lock);
> -
> -	RAW_INIT_NOTIFIER_HEAD(&edev->nh);
> +	edev->extcon_dev_type.name = dev_name(&edev->dev);
> +	edev->extcon_dev_type.release = dummy_sysfs_dev_release;
>  
> -	dev_set_drvdata(&edev->dev, edev);
> -	edev->state = 0;
> +	for (index = 0; index < edev->max_supported; index++)
> +		edev->extcon_dev_type.groups[index] =
> +			&edev->cables[index].attr_g;
> +	if (edev->mutually_exclusive)
> +		edev->extcon_dev_type.groups[index] =
> +			&edev->attr_g_muex;
>  
> -	mutex_lock(&extcon_dev_list_lock);
> -	list_add(&edev->entry, &extcon_dev_list);
> -	mutex_unlock(&extcon_dev_list_lock);
> +	edev->dev.type = &edev->extcon_dev_type;
>  
> -	return 0;
> +	return edev;
>  
> -err_dev:
> -	if (edev->max_supported)
> -		kfree(edev->extcon_dev_type.groups);
>  err_alloc_groups:
> -	if (edev->max_supported && edev->mutually_exclusive) {
> +	if (edev->mutually_exclusive) {
>  		for (index = 0; edev->mutually_exclusive[index]; index++)
>  			kfree(edev->d_attrs_muex[index].attr.name);
>  		kfree(edev->d_attrs_muex);
> @@ -765,36 +811,22 @@ err_muex:
>  	for (index = 0; index < edev->max_supported; index++)
>  		kfree(edev->cables[index].attr_g.name);
>  err_alloc_cables:
> -	if (edev->max_supported)
> -		kfree(edev->cables);
> -err_sysfs_alloc:
> -	return ret;
> +	kfree(edev->cables);
> +err:
> +	kfree(edev);
> +
> +	return ERR_PTR(ret);
>  }
> -EXPORT_SYMBOL_GPL(extcon_dev_register);
> +EXPORT_SYMBOL_GPL(extcon_dev_allocate);
>  
> -/**
> - * extcon_dev_unregister() - Unregister the extcon device.
> - * @edev:	the extcon device instance to be unregistered.
> - *
> - * Note that this does not call kfree(edev) because edev was not allocated
> - * by this class.
> +/*
> + * extcon_dev_free() - Free the memory of extcon device.
> + * @edev:	the extcon device to free
>   */
> -void extcon_dev_unregister(struct extcon_dev *edev)
> +void extcon_dev_free(struct extcon_dev *edev)
>  {
>  	int index;
>  
> -	mutex_lock(&extcon_dev_list_lock);
> -	list_del(&edev->entry);
> -	mutex_unlock(&extcon_dev_list_lock);
> -
> -	if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
> -		dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
> -				dev_name(&edev->dev));
> -		return;
> -	}
> -
> -	device_unregister(&edev->dev);
> -
>  	if (edev->mutually_exclusive && edev->max_supported) {
>  		for (index = 0; edev->mutually_exclusive[index];
>  				index++)
> @@ -811,13 +843,10 @@ void extcon_dev_unregister(struct extcon_dev *edev)
>  		kfree(edev->cables);
>  	}
>  
> -#if defined(CONFIG_ANDROID)
> -	if (switch_class)
> -		class_compat_remove_link(switch_class, &edev->dev, NULL);
> -#endif
> -	put_device(&edev->dev);
> +	if (edev)
> +		put_device(&edev->dev);
>  }
> -EXPORT_SYMBOL_GPL(extcon_dev_unregister);
> +EXPORT_SYMBOL_GPL(extcon_dev_free);
>  
>  static void devm_extcon_dev_unreg(struct device *dev, void *res)
>  {
> diff --git a/include/linux/extcon.h b/include/linux/extcon.h
> index 85a8a5b..20587ee 100644
> --- a/include/linux/extcon.h
> +++ b/include/linux/extcon.h
> @@ -179,6 +179,8 @@ struct extcon_specific_cable_nb {
>  
>  #if IS_ENABLED(CONFIG_EXTCON)
>  
> +#define dev_to_extcon_dev(d) container_of(d, struct extcon_dev, dev)
> +
>  /*
>   * Following APIs are for notifiers or configurations.
>   * Notifiers are the external port and connection devices.
> @@ -250,6 +252,12 @@ extern int extcon_unregister_notifier(struct extcon_dev *edev,
>  				      struct notifier_block *nb);
>  
>  /*
> + * Following APIs control the memory of extcon device.
> + */
> +extern struct extcon_dev *extcon_dev_allocate(const char **cables);
> +extern void extcon_dev_free(struct extcon_dev *edev);
> +
> +/*
>   * Following API get the extcon device from devicetree.
>   * This function use phandle of devicetree to get extcon device directly.
>   */
> @@ -353,5 +361,12 @@ static inline struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev,
>  {
>  	return ERR_PTR(-ENODEV);
>  }
> +
> +static inline struct extcon_dev *extcon_dev_allocate(const char **cables)
> +{
> +	return ERR_PTR(-ENOMEM);
> +}
> +
> +static inline void extcon_dev_free(struct extcon_dev *edev) { }
>  #endif /* CONFIG_EXTCON */
>  #endif /* __LINUX_EXTCON_H__ */
> 
> 
> here's full bisection log:
> 
> git bisect start
> # good: [a798c10faf62a505d24e5f6213fbaf904a39623f] Linux 3.15-rc2
> git bisect good a798c10faf62a505d24e5f6213fbaf904a39623f
> # bad: [3019b77470c1f10b23438917f73cad386e4f7f02] Merge branch 'extcon-next' of git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/extcon into merge
> git bisect bad 3019b77470c1f10b23438917f73cad386e4f7f02
> # bad: [f68f3aeb530b1efe3d6bf583db7a6255d15544eb] extcon: max14577: Use devm_extcon_dev_allocate for extcon_dev
> git bisect bad f68f3aeb530b1efe3d6bf583db7a6255d15544eb
> # good: [489096faca790b75653478d2f9d4774dd4f07b93] extcon: gpio: Use devm_extcon_dev_register()
> git bisect good 489096faca790b75653478d2f9d4774dd4f07b93
> # good: [5a451cded8793798e0d409e6ed6f8c53785ae929] extcon: arizona: Use devm_extcon_dev_register()
> git bisect good 5a451cded8793798e0d409e6ed6f8c53785ae929
> # bad: [cbe68e2d93df61fe40ddfea4d75f169fabadc155] extcon: Add devm_extcon_dev_allocate/free to manage the resource of extcon device
> git bisect bad cbe68e2d93df61fe40ddfea4d75f169fabadc155
> # bad: [854b85057cc6b90a326b731174b6c6dbbf34222a] extcon: Add extcon_dev_allocate/free() to control the memory of extcon device
> git bisect bad 854b85057cc6b90a326b731174b6c6dbbf34222a
> # first bad commit: [854b85057cc6b90a326b731174b6c6dbbf34222a] extcon: Add extcon_dev_allocate/free() to control the memory of extcon device
> 
> And the bug is very simple and affects *all* users of extcon class,
> which tells me that this big series switching over to devm_* resources
> wasn't tested at all. Originally extcon_dev_register() was calling
> device_register(&edev->dev) which will call device_initialize(dev)
> followed by device_add(dev).
> 
> After this commit, extcon_dev_register() now calls
> device_add(&edev->dev) directly but never calls device_initialize()
> anywhere. Was this *ever* tested anywhere ????? I suppose not!
> 
> Please fix that up ASAP.

After fixing (actually, hacking) the first problem:


I tested this on OMAP5 but there's still *another* regression, it takes
some 15 seconds for enumeration to happen after cable is attached:

[  126.476804] palmas-usb palmas_usb.7: USB cable is attached
[  141.912688] g_mass_storage gadget: super-speed config #1: Linux File-Backed Storage

Dure, seriously ??? I'll continue debugging this, but god damn!!!!

cheers

Comments

Chanwoo Choi April 24, 2014, 5:35 a.m. UTC | #1
Hi Felipe,

Thanks for your test and review.

On 04/24/2014 03:28 AM, Felipe Balbi wrote:
> Hi,
> 
> On Wed, Apr 23, 2014 at 12:20:52PM -0500, Felipe Balbi wrote:
>>> I've been testing extcon-next to make sure USB3 on OMAP5 will work out
>>> of the box but I see a regression when I merge your tree on top of
>>> v3.15-rc2 + Tony's DT fixes.
>>>
>>> Here's what I see (trimmed):
>>>
>>> [    1.805870] palmas 0-0048: Muxing GPIO 2, PWM 0, LED 0
>>> [    1.812516] ------------[ cut here ]------------
>>> [    1.817387] WARNING: CPU: 0 PID: 6 at include/linux/kref.h:47 kobject_get+0x64/0x78()
>>> [    1.817691]  mmcblk0boot1: unknown partition table
>>> [    1.830601] Modules linked in:
>>> [    1.833827] CPU: 0 PID: 6 Comm: kworker/u4:0 Tainted: G        W     3.15.0-rc2-00041-g3019b77 #308
>>> [    1.843333] Workqueue: deferwq deferred_probe_work_func
>>> [    1.848728]  mmcblk0boot0: unknown partition table
>>> [    1.853928] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
>>> [    1.862086] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
>>> [    1.869667] [<c05426b4>] (dump_stack) from [<c0040928>] (warn_slowpath_common+0x6c/0x90)
>>> [    1.878181] [<c0040928>] (warn_slowpath_common) from [<c00409e8>] (warn_slowpath_null+0x1c/0x24)
>>> [    1.887421] [<c00409e8>] (warn_slowpath_null) from [<c02d50c4>] (kobject_get+0x64/0x78)
>>> [    1.895837] [<c02d50c4>] (kobject_get) from [<c0350188>] (device_add+0x18/0x520)
>>> [    1.903629] [<c0350188>] (device_add) from [<c0462a5c>] (extcon_dev_register+0x48/0x104)
>>> [    1.912145] [<c0462a5c>] (extcon_dev_register) from [<c0462b44>] (devm_extcon_dev_register+0x2c/0x68)
>>> [    1.921847] [<c0462b44>] (devm_extcon_dev_register) from [<c04630c0>] (palmas_usb_probe+0x110/0x304)
>>> [    1.931453] [<c04630c0>] (palmas_usb_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
>>> [    1.940333] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>> [    1.949664] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>> [    1.958634] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>> [    1.967003] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>> [    1.975387] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
>>> [    1.983678] [<c0350590>] (device_add) from [<c045a310>] (of_platform_device_create_pdata+0x6c/0x8c)
>>> [    1.993155] [<c045a310>] (of_platform_device_create_pdata) from [<c045a418>] (of_platform_bus_create+0xdc/0x168)
>>> [    2.003818] [<c045a418>] (of_platform_bus_create) from [<c045a5cc>] (of_platform_populate+0x5c/0xa0)
>>> [    2.013399] [<c045a5cc>] (of_platform_populate) from [<c0373c78>] (palmas_i2c_probe+0x30c/0x584)
>>> [    2.022606] [<c0373c78>] (palmas_i2c_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>> [    2.031722] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>> [    2.040715] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>> [    2.049098] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>> [    2.057482] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
>>> [    2.065774] [<c0350590>] (device_add) from [<c0424020>] (i2c_new_device+0x12c/0x18c)
>>> [    2.073885] [<c0424020>] (i2c_new_device) from [<c0424980>] (i2c_register_adapter+0x278/0x498)
>>> [    2.082903] [<c0424980>] (i2c_register_adapter) from [<c04275c0>] (omap_i2c_probe+0x4a4/0x6d0)
>>> [    2.091925] [<c04275c0>] (omap_i2c_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
>>> [    2.100582] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>> [    2.109883] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>> [    2.118823] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>> [    2.127194] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>> [    2.135584] [<c035206c>] (bus_probe_device) from [<c03524ac>] (deferred_probe_work_func+0x64/0x94)
>>> [    2.144975] [<c03524ac>] (deferred_probe_work_func) from [<c0058c70>] (process_one_work+0x1ac/0x4cc)
>>> [    2.154545] [<c0058c70>] (process_one_work) from [<c0059b10>] (worker_thread+0x114/0x3b4)
>>> [    2.163119] [<c0059b10>] (worker_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
>>> [    2.170695] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
>>> [    2.178259] ---[ end trace 3006de6450234d28 ]---
>>> [    2.183081] kobject 'palmas_usb' (eca58c38): tried to add an uninitialized object, something is seriously wrong.
>>> [    2.193731] CPU: 0 PID: 6 Comm: kworker/u4:0 Tainted: G        W     3.15.0-rc2-00041-g3019b77 #308
>>> [    2.203201] Workqueue: deferwq deferred_probe_work_func
>>> [    2.208687] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
>>> [    2.216789] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
>>> [    2.224357] [<c05426b4>] (dump_stack) from [<c02d5c28>] (kobject_add+0x88/0x98)
>>> [    2.232014] [<c02d5c28>] (kobject_add) from [<c0350250>] (device_add+0xe0/0x520)
>>> [    2.239758] [<c0350250>] (device_add) from [<c0462a5c>] (extcon_dev_register+0x48/0x104)
>>> [    2.248235] [<c0462a5c>] (extcon_dev_register) from [<c0462b44>] (devm_extcon_dev_register+0x2c/0x68)
>>> [    2.257901] [<c0462b44>] (devm_extcon_dev_register) from [<c04630c0>] (palmas_usb_probe+0x110/0x304)
>>> [    2.267467] [<c04630c0>] (palmas_usb_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
>>> [    2.276298] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>> [    2.285591] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>> [    2.294520] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>> [    2.302905] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>> [    2.311286] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
>>> [    2.319583] [<c0350590>] (device_add) from [<c045a310>] (of_platform_device_create_pdata+0x6c/0x8c)
>>> [    2.329063] [<c045a310>] (of_platform_device_create_pdata) from [<c045a418>] (of_platform_bus_create+0xdc/0x168)
>>> [    2.339725] [<c045a418>] (of_platform_bus_create) from [<c045a5cc>] (of_platform_populate+0x5c/0xa0)
>>> [    2.349296] [<c045a5cc>] (of_platform_populate) from [<c0373c78>] (palmas_i2c_probe+0x30c/0x584)
>>> [    2.358496] [<c0373c78>] (palmas_i2c_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>> [    2.367609] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>> [    2.376523] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>> [    2.384914] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>> [    2.393301] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
>>> [    2.401601] [<c0350590>] (device_add) from [<c0424020>] (i2c_new_device+0x12c/0x18c)
>>> [    2.409707] [<c0424020>] (i2c_new_device) from [<c0424980>] (i2c_register_adapter+0x278/0x498)
>>> [    2.418727] [<c0424980>] (i2c_register_adapter) from [<c04275c0>] (omap_i2c_probe+0x4a4/0x6d0)
>>> [    2.427741] [<c04275c0>] (omap_i2c_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
>>> [    2.436382] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>> [    2.445680] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>> [    2.454613] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>> [    2.463001] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>> [    2.471385] [<c035206c>] (bus_probe_device) from [<c03524ac>] (deferred_probe_work_func+0x64/0x94)
>>> [    2.480772] [<c03524ac>] (deferred_probe_work_func) from [<c0058c70>] (process_one_work+0x1ac/0x4cc)
>>> [    2.490339] [<c0058c70>] (process_one_work) from [<c0059b10>] (worker_thread+0x114/0x3b4)
>>> [    2.498906] [<c0059b10>] (worker_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
>>> [    2.506460] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
>>> [    2.514023] ------------[ cut here ]------------
>>> [    2.518870] WARNING: CPU: 0 PID: 6 at lib/kobject.c:670 kobject_put+0x80/0x90()
>>> [    2.526514] kobject: 'palmas_usb' (eca58c38): is not initialized, yet kobject_put() is being called.
>>> [    2.536076] Modules linked in:
>>> [    2.539287] CPU: 0 PID: 6 Comm: kworker/u4:0 Tainted: G        W     3.15.0-rc2-00041-g3019b77 #308
>>> [    2.548753] Workqueue: deferwq deferred_probe_work_func
>>> [    2.554223] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
>>> [    2.562341] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
>>> [    2.569911] [<c05426b4>] (dump_stack) from [<c0040928>] (warn_slowpath_common+0x6c/0x90)
>>> [    2.578391] [<c0040928>] (warn_slowpath_common) from [<c004097c>] (warn_slowpath_fmt+0x30/0x40)
>>> [    2.587502] [<c004097c>] (warn_slowpath_fmt) from [<c02d5158>] (kobject_put+0x80/0x90)
>>> [    2.595780] [<c02d5158>] (kobject_put) from [<c03502fc>] (device_add+0x18c/0x520)
>>> [    2.603623] [<c03502fc>] (device_add) from [<c0462a5c>] (extcon_dev_register+0x48/0x104)
>>> [    2.612103] [<c0462a5c>] (extcon_dev_register) from [<c0462b44>] (devm_extcon_dev_register+0x2c/0x68)
>>> [    2.621762] [<c0462b44>] (devm_extcon_dev_register) from [<c04630c0>] (palmas_usb_probe+0x110/0x304)
>>> [    2.631321] [<c04630c0>] (palmas_usb_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
>>> [    2.640161] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>> [    2.649447] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>> [    2.658386] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>> [    2.666757] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>> [    2.675144] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
>>> [    2.683441] [<c0350590>] (device_add) from [<c045a310>] (of_platform_device_create_pdata+0x6c/0x8c)
>>> [    2.692921] [<c045a310>] (of_platform_device_create_pdata) from [<c045a418>] (of_platform_bus_create+0xdc/0x168)
>>> [    2.703575] [<c045a418>] (of_platform_bus_create) from [<c045a5cc>] (of_platform_populate+0x5c/0xa0)
>>> [    2.713139] [<c045a5cc>] (of_platform_populate) from [<c0373c78>] (palmas_i2c_probe+0x30c/0x584)
>>> [    2.722341] [<c0373c78>] (palmas_i2c_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>> [    2.731457] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>> [    2.740380] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>> [    2.748764] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>> [    2.757135] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
>>> [    2.765429] [<c0350590>] (device_add) from [<c0424020>] (i2c_new_device+0x12c/0x18c)
>>> [    2.773549] [<c0424020>] (i2c_new_device) from [<c0424980>] (i2c_register_adapter+0x278/0x498)
>>> [    2.782576] [<c0424980>] (i2c_register_adapter) from [<c04275c0>] (omap_i2c_probe+0x4a4/0x6d0)
>>> [    2.791597] [<c04275c0>] (omap_i2c_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
>>> [    2.800261] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>> [    2.809560] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>> [    2.818489] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>> [    2.826865] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>> [    2.835253] [<c035206c>] (bus_probe_device) from [<c03524ac>] (deferred_probe_work_func+0x64/0x94)
>>> [    2.844637] [<c03524ac>] (deferred_probe_work_func) from [<c0058c70>] (process_one_work+0x1ac/0x4cc)
>>> [    2.854205] [<c0058c70>] (process_one_work) from [<c0059b10>] (worker_thread+0x114/0x3b4)
>>> [    2.862778] [<c0059b10>] (worker_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
>>> [    2.870349] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
>>> [    2.877911] ---[ end trace 3006de6450234d29 ]---
>>> [    2.882734] ------------[ cut here ]------------
>>> [    2.887573] WARNING: CPU: 0 PID: 6 at lib/kobject.c:670 kobject_put+0x80/0x90()
>>> [    2.895209] kobject: 'palmas_usb' (eca58c38): is not initialized, yet kobject_put() is being called.
>>> [    2.904765] Modules linked in:
>>> [    2.907971] CPU: 0 PID: 6 Comm: kworker/u4:0 Tainted: G        W     3.15.0-rc2-00041-g3019b77 #308
>>> [    2.917447] Workqueue: deferwq deferred_probe_work_func
>>> [    2.922924] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
>>> [    2.931033] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
>>> [    2.938606] [<c05426b4>] (dump_stack) from [<c0040928>] (warn_slowpath_common+0x6c/0x90)
>>> [    2.947069] [<c0040928>] (warn_slowpath_common) from [<c004097c>] (warn_slowpath_fmt+0x30/0x40)
>>> [    2.956187] [<c004097c>] (warn_slowpath_fmt) from [<c02d5158>] (kobject_put+0x80/0x90)
>>> [    2.964483] [<c02d5158>] (kobject_put) from [<c0462abc>] (extcon_dev_register+0xa8/0x104)
>>> [    2.973053] [<c0462abc>] (extcon_dev_register) from [<c0462b44>] (devm_extcon_dev_register+0x2c/0x68)
>>> [    2.982718] [<c0462b44>] (devm_extcon_dev_register) from [<c04630c0>] (palmas_usb_probe+0x110/0x304)
>>> [    2.992285] [<c04630c0>] (palmas_usb_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
>>> [    3.001124] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>> [    3.010423] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>> [    3.019358] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>> [    3.027746] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>> [    3.036121] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
>>> [    3.044418] [<c0350590>] (device_add) from [<c045a310>] (of_platform_device_create_pdata+0x6c/0x8c)
>>> [    3.053893] [<c045a310>] (of_platform_device_create_pdata) from [<c045a418>] (of_platform_bus_create+0xdc/0x168)
>>> [    3.064550] [<c045a418>] (of_platform_bus_create) from [<c045a5cc>] (of_platform_populate+0x5c/0xa0)
>>> [    3.074124] [<c045a5cc>] (of_platform_populate) from [<c0373c78>] (palmas_i2c_probe+0x30c/0x584)
>>> [    3.083338] [<c0373c78>] (palmas_i2c_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>> [    3.092447] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>> [    3.101381] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>> [    3.109767] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>> [    3.118147] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
>>> [    3.126432] [<c0350590>] (device_add) from [<c0424020>] (i2c_new_device+0x12c/0x18c)
>>> [    3.134547] [<c0424020>] (i2c_new_device) from [<c0424980>] (i2c_register_adapter+0x278/0x498)
>>> [    3.143569] [<c0424980>] (i2c_register_adapter) from [<c04275c0>] (omap_i2c_probe+0x4a4/0x6d0)
>>> [    3.152593] [<c04275c0>] (omap_i2c_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
>>> [    3.161249] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>> [    3.170537] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>> [    3.179472] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>> [    3.187854] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>> [    3.196222] [<c035206c>] (bus_probe_device) from [<c03524ac>] (deferred_probe_work_func+0x64/0x94)
>>> [    3.205611] [<c03524ac>] (deferred_probe_work_func) from [<c0058c70>] (process_one_work+0x1ac/0x4cc)
>>> [    3.215174] [<c0058c70>] (process_one_work) from [<c0059b10>] (worker_thread+0x114/0x3b4)
>>> [    3.223739] [<c0059b10>] (worker_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
>>> [    3.231313] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
>>> [    3.238883] ---[ end trace 3006de6450234d2a ]---
>>> [    3.243711] palmas-usb palmas_usb.7: failed to register extcon device
>>> [    3.250493] palmas-usb: probe of palmas_usb.7 failed with error -22
>>>
>>> Any ideas ??
>>
>> bisected down to:
>>
>> commit 854b85057cc6b90a326b731174b6c6dbbf34222a
>> Author: Chanwoo Choi <cw00.choi@samsung.com>
>> Date:   Mon Apr 21 19:46:51 2014 +0900
>>
>>     extcon: Add extcon_dev_allocate/free() to control the memory of extcon device
>>     
>>     This patch add APIs to control the extcon device on extcon provider driver.
>>     The extcon_dev_allocate() allocates the memory of extcon device and initializes
>>     supported cables. And then extcon_dev_free() decrement the reference of the
>>     device of extcon device and free the memory of the extcon device. This APIs
>>     must need to implement devm_extcon_dev_allocate()/free() APIs.
>>     
>>     Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
>>
>> diff --git a/drivers/extcon/extcon-class.c b/drivers/extcon/extcon-class.c
>> index f6df689..3e485bc 100644
>> --- a/drivers/extcon/extcon-class.c
>> +++ b/drivers/extcon/extcon-class.c
>> @@ -558,6 +558,9 @@ static int create_extcon_class(void)
>>  
>>  static void extcon_dev_release(struct device *dev)
>>  {
>> +	struct extcon_dev *edev = dev_to_extcon_dev(dev);
>> +
>> +	kfree(edev);
>>  }
>>  
>>  static const char *muex_name = "mutually_exclusive";
>> @@ -576,7 +579,7 @@ static void dummy_sysfs_dev_release(struct device *dev)
>>   */
>>  int extcon_dev_register(struct extcon_dev *edev)
>>  {
>> -	int ret, index = 0;
>> +	int ret;
>>  
>>  	if (!extcon_class) {
>>  		ret = create_extcon_class();
>> @@ -584,80 +587,150 @@ int extcon_dev_register(struct extcon_dev *edev)
>>  			return ret;
>>  	}
>>  
>> -	if (edev->supported_cable) {
>> -		/* Get size of array */
>> -		for (index = 0; edev->supported_cable[index]; index++)
>> -			;
>> -		edev->max_supported = index;
>> -	} else {
>> -		edev->max_supported = 0;
>> +	edev->name = edev->name ? edev->name : dev_name(edev->dev.parent);
>> +	if (IS_ERR_OR_NULL(edev->name)) {
>> +		dev_err(&edev->dev, "extcon device name is null\n");
>> +		return -EINVAL;
>>  	}
>> +	dev_set_name(&edev->dev, "%s", edev->name);
>>  
>> -	if (index > SUPPORTED_CABLE_MAX) {
>> -		dev_err(&edev->dev, "extcon: maximum number of supported cables exceeded.\n");
>> -		return -EINVAL;
>> +	ret = device_add(&edev->dev);
>> +	if (ret) {
>> +		put_device(&edev->dev);
>> +		return ret;
>>  	}
>> +#if defined(CONFIG_ANDROID)
>> +	if (switch_class)
>> +		ret = class_compat_create_link(switch_class, &edev->dev, NULL);
>> +#endif /* CONFIG_ANDROID */
>>  
>> -	edev->dev.class = extcon_class;
>> -	edev->dev.release = extcon_dev_release;
>> +	RAW_INIT_NOTIFIER_HEAD(&edev->nh);
>>  
>> -	edev->name = edev->name ? edev->name : dev_name(edev->dev.parent);
>> -	if (IS_ERR_OR_NULL(edev->name)) {
>> -		dev_err(&edev->dev,
>> -			"extcon device name is null\n");
>> -		return -EINVAL;
>> +	dev_set_drvdata(&edev->dev, edev);
>> +	edev->state = 0;
>> +
>> +	mutex_lock(&extcon_dev_list_lock);
>> +	list_add(&edev->entry, &extcon_dev_list);
>> +	mutex_unlock(&extcon_dev_list_lock);
>> +
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(extcon_dev_register);
>> +
>> +/**
>> + * extcon_dev_unregister() - Unregister the extcon device.
>> + * @edev:	the extcon device instance to be unregistered.
>> + */
>> +void extcon_dev_unregister(struct extcon_dev *edev)
>> +{
>> +	mutex_lock(&extcon_dev_list_lock);
>> +	list_del(&edev->entry);
>> +	mutex_unlock(&extcon_dev_list_lock);
>> +
>> +	if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
>> +		dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
>> +				dev_name(&edev->dev));
>> +		return;
>>  	}
>> -	dev_set_name(&edev->dev, "%s", edev->name);
>>  
>> -	if (edev->max_supported) {
>> -		char buf[10];
>> -		char *str;
>> -		struct extcon_cable *cable;
>> +	device_unregister(&edev->dev);
>>  
>> -		edev->cables = kzalloc(sizeof(struct extcon_cable) *
>> -				       edev->max_supported, GFP_KERNEL);
>> -		if (!edev->cables) {
>> +#if defined(CONFIG_ANDROID)
>> +	if (switch_class)
>> +		class_compat_remove_link(switch_class, &edev->dev, NULL);
>> +#endif
>> +}
>> +EXPORT_SYMBOL_GPL(extcon_dev_unregister);
>> +
>> +/*
>> + * extcon_dev_allocate() - Allocate the memory of extcon device.
>> + * @supported_cable:	Array of supported cable names ending with NULL.
>> + *			If supported_cable is NULL, cable name related APIs
>> + *			are disabled.
>> + *
>> + * This function allocates the memory for extcon device without allocating
>> + * memory in each extcon provider driver and initialize default setting for
>> + * extcon device.
>> + *
>> + * Return the pointer of extcon device if success or ERR_PTR(err) if fail
>> + */
>> +struct extcon_dev *extcon_dev_allocate(const char **supported_cable)
>> +{
>> +	struct extcon_dev *edev;
>> +	int index, ret, count = 0;
>> +
>> +	edev = kzalloc(sizeof(*edev), GFP_KERNEL);
>> +	if (!edev) {
>> +		pr_err("Failed to allocate the memory for extcon device\n");
>> +		return ERR_PTR(-ENOMEM);
>> +	}
>> +
>> +	edev->max_supported = 0;
>> +	edev->supported_cable = supported_cable;
>> +	if (edev->supported_cable) {
>> +		for (count = 0; edev->supported_cable[count]; count++)
>> +			;
>> +		edev->max_supported = count;
>> +		if (count > SUPPORTED_CABLE_MAX) {
>> +			pr_err("Exceed max number of supported cables\n");
>>  			ret = -ENOMEM;
>> -			goto err_sysfs_alloc;
>> +			goto err;
>>  		}
>> -		for (index = 0; index < edev->max_supported; index++) {
>> -			cable = &edev->cables[index];
>> +	}
>>  
>> -			snprintf(buf, 10, "cable.%d", index);
>> -			str = kzalloc(sizeof(char) * (strlen(buf) + 1),
>> -				      GFP_KERNEL);
>> -			if (!str) {
>> -				for (index--; index >= 0; index--) {
>> -					cable = &edev->cables[index];
>> -					kfree(cable->attr_g.name);
>> -				}
>> -				ret = -ENOMEM;
>> +	edev->dev.class = extcon_class;
>> +	edev->dev.release = extcon_dev_release;
>> +	device_initialize(&edev->dev);
>> +	spin_lock_init(&edev->lock);
>> +
>> +	if (!edev->max_supported)
>> +		return 0;
>> +
>> +	edev->cables = kzalloc(sizeof(struct extcon_cable) *
>> +			       edev->max_supported, GFP_KERNEL);
>> +	if (!edev->cables) {
>> +		ret = -ENOMEM;
>> +		goto err;
>> +	}
>>  
>> -				goto err_alloc_cables;
>> +	for (index = 0; index < edev->max_supported; index++) {
>> +		struct extcon_cable *cable = &edev->cables[index];
>> +		char buf[10];
>> +		char *str;
>> +
>> +		snprintf(buf, 10, "cable.%d", index);
>> +		str = kzalloc(sizeof(char) * (strlen(buf) + 1),
>> +			      GFP_KERNEL);
>> +		if (!str) {
>> +			for (index--; index >= 0; index--) {
>> +				cable = &edev->cables[index];
>> +				kfree(cable->attr_g.name);
>>  			}
>> -			strcpy(str, buf);
>> -
>> -			cable->edev = edev;
>> -			cable->cable_index = index;
>> -			cable->attrs[0] = &cable->attr_name.attr;
>> -			cable->attrs[1] = &cable->attr_state.attr;
>> -			cable->attrs[2] = NULL;
>> -			cable->attr_g.name = str;
>> -			cable->attr_g.attrs = cable->attrs;
>> -
>> -			sysfs_attr_init(&cable->attr_name.attr);
>> -			cable->attr_name.attr.name = "name";
>> -			cable->attr_name.attr.mode = 0444;
>> -			cable->attr_name.show = cable_name_show;
>> -
>> -			sysfs_attr_init(&cable->attr_state.attr);
>> -			cable->attr_state.attr.name = "state";
>> -			cable->attr_state.attr.mode = 0444;
>> -			cable->attr_state.show = cable_state_show;
>> +			ret = -ENOMEM;
>> +			goto err_alloc_cables;
>>  		}
>> +		strcpy(str, buf);
>> +
>> +		cable->edev = edev;
>> +		cable->cable_index = index;
>> +		cable->attrs[0] = &cable->attr_name.attr;
>> +		cable->attrs[1] = &cable->attr_state.attr;
>> +		cable->attrs[2] = NULL;
>> +		cable->attr_g.name = str;
>> +		cable->attr_g.attrs = cable->attrs;
>> +
>> +		sysfs_attr_init(&cable->attr_name.attr);
>> +		cable->attr_name.attr.name = "name";
>> +		cable->attr_name.attr.mode = 0444;
>> +		cable->attr_name.show = cable_name_show;
>> +
>> +		sysfs_attr_init(&cable->attr_state.attr);
>> +		cable->attr_state.attr.name = "state";
>> +		cable->attr_state.attr.mode = 0444;
>> +		cable->attr_state.show = cable_state_show;
>>  	}
>>  
>> -	if (edev->max_supported && edev->mutually_exclusive) {
>> +	if (edev->mutually_exclusive) {
>>  		char buf[80];
>>  		char *name;
>>  
>> @@ -703,59 +776,32 @@ int extcon_dev_register(struct extcon_dev *edev)
>>  		}
>>  		edev->attr_g_muex.name = muex_name;
>>  		edev->attr_g_muex.attrs = edev->attrs_muex;
>> -
>>  	}
>>  
>> -	if (edev->max_supported) {
>> -		edev->extcon_dev_type.groups =
>> -			kzalloc(sizeof(struct attribute_group *) *
>> -				(edev->max_supported + 2), GFP_KERNEL);
>> -		if (!edev->extcon_dev_type.groups) {
>> -			ret = -ENOMEM;
>> -			goto err_alloc_groups;
>> -		}
>> -
>> -		edev->extcon_dev_type.name = dev_name(&edev->dev);
>> -		edev->extcon_dev_type.release = dummy_sysfs_dev_release;
>> -
>> -		for (index = 0; index < edev->max_supported; index++)
>> -			edev->extcon_dev_type.groups[index] =
>> -				&edev->cables[index].attr_g;
>> -		if (edev->mutually_exclusive)
>> -			edev->extcon_dev_type.groups[index] =
>> -				&edev->attr_g_muex;
>> -
>> -		edev->dev.type = &edev->extcon_dev_type;
>> +	edev->extcon_dev_type.groups =
>> +		kzalloc(sizeof(struct attribute_group *) *
>> +			(edev->max_supported + 2), GFP_KERNEL);
>> +	if (!edev->extcon_dev_type.groups) {
>> +		ret = -ENOMEM;
>> +		goto err_alloc_groups;
>>  	}
>>  
>> -	ret = device_register(&edev->dev);
>> -	if (ret) {
>> -		put_device(&edev->dev);
>> -		goto err_dev;
>> -	}
>> -#if defined(CONFIG_ANDROID)
>> -	if (switch_class)
>> -		ret = class_compat_create_link(switch_class, &edev->dev, NULL);
>> -#endif /* CONFIG_ANDROID */
>> -
>> -	spin_lock_init(&edev->lock);
>> -
>> -	RAW_INIT_NOTIFIER_HEAD(&edev->nh);
>> +	edev->extcon_dev_type.name = dev_name(&edev->dev);
>> +	edev->extcon_dev_type.release = dummy_sysfs_dev_release;
>>  
>> -	dev_set_drvdata(&edev->dev, edev);
>> -	edev->state = 0;
>> +	for (index = 0; index < edev->max_supported; index++)
>> +		edev->extcon_dev_type.groups[index] =
>> +			&edev->cables[index].attr_g;
>> +	if (edev->mutually_exclusive)
>> +		edev->extcon_dev_type.groups[index] =
>> +			&edev->attr_g_muex;
>>  
>> -	mutex_lock(&extcon_dev_list_lock);
>> -	list_add(&edev->entry, &extcon_dev_list);
>> -	mutex_unlock(&extcon_dev_list_lock);
>> +	edev->dev.type = &edev->extcon_dev_type;
>>  
>> -	return 0;
>> +	return edev;
>>  
>> -err_dev:
>> -	if (edev->max_supported)
>> -		kfree(edev->extcon_dev_type.groups);
>>  err_alloc_groups:
>> -	if (edev->max_supported && edev->mutually_exclusive) {
>> +	if (edev->mutually_exclusive) {
>>  		for (index = 0; edev->mutually_exclusive[index]; index++)
>>  			kfree(edev->d_attrs_muex[index].attr.name);
>>  		kfree(edev->d_attrs_muex);
>> @@ -765,36 +811,22 @@ err_muex:
>>  	for (index = 0; index < edev->max_supported; index++)
>>  		kfree(edev->cables[index].attr_g.name);
>>  err_alloc_cables:
>> -	if (edev->max_supported)
>> -		kfree(edev->cables);
>> -err_sysfs_alloc:
>> -	return ret;
>> +	kfree(edev->cables);
>> +err:
>> +	kfree(edev);
>> +
>> +	return ERR_PTR(ret);
>>  }
>> -EXPORT_SYMBOL_GPL(extcon_dev_register);
>> +EXPORT_SYMBOL_GPL(extcon_dev_allocate);
>>  
>> -/**
>> - * extcon_dev_unregister() - Unregister the extcon device.
>> - * @edev:	the extcon device instance to be unregistered.
>> - *
>> - * Note that this does not call kfree(edev) because edev was not allocated
>> - * by this class.
>> +/*
>> + * extcon_dev_free() - Free the memory of extcon device.
>> + * @edev:	the extcon device to free
>>   */
>> -void extcon_dev_unregister(struct extcon_dev *edev)
>> +void extcon_dev_free(struct extcon_dev *edev)
>>  {
>>  	int index;
>>  
>> -	mutex_lock(&extcon_dev_list_lock);
>> -	list_del(&edev->entry);
>> -	mutex_unlock(&extcon_dev_list_lock);
>> -
>> -	if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
>> -		dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
>> -				dev_name(&edev->dev));
>> -		return;
>> -	}
>> -
>> -	device_unregister(&edev->dev);
>> -
>>  	if (edev->mutually_exclusive && edev->max_supported) {
>>  		for (index = 0; edev->mutually_exclusive[index];
>>  				index++)
>> @@ -811,13 +843,10 @@ void extcon_dev_unregister(struct extcon_dev *edev)
>>  		kfree(edev->cables);
>>  	}
>>  
>> -#if defined(CONFIG_ANDROID)
>> -	if (switch_class)
>> -		class_compat_remove_link(switch_class, &edev->dev, NULL);
>> -#endif
>> -	put_device(&edev->dev);
>> +	if (edev)
>> +		put_device(&edev->dev);
>>  }
>> -EXPORT_SYMBOL_GPL(extcon_dev_unregister);
>> +EXPORT_SYMBOL_GPL(extcon_dev_free);
>>  
>>  static void devm_extcon_dev_unreg(struct device *dev, void *res)
>>  {
>> diff --git a/include/linux/extcon.h b/include/linux/extcon.h
>> index 85a8a5b..20587ee 100644
>> --- a/include/linux/extcon.h
>> +++ b/include/linux/extcon.h
>> @@ -179,6 +179,8 @@ struct extcon_specific_cable_nb {
>>  
>>  #if IS_ENABLED(CONFIG_EXTCON)
>>  
>> +#define dev_to_extcon_dev(d) container_of(d, struct extcon_dev, dev)
>> +
>>  /*
>>   * Following APIs are for notifiers or configurations.
>>   * Notifiers are the external port and connection devices.
>> @@ -250,6 +252,12 @@ extern int extcon_unregister_notifier(struct extcon_dev *edev,
>>  				      struct notifier_block *nb);
>>  
>>  /*
>> + * Following APIs control the memory of extcon device.
>> + */
>> +extern struct extcon_dev *extcon_dev_allocate(const char **cables);
>> +extern void extcon_dev_free(struct extcon_dev *edev);
>> +
>> +/*
>>   * Following API get the extcon device from devicetree.
>>   * This function use phandle of devicetree to get extcon device directly.
>>   */
>> @@ -353,5 +361,12 @@ static inline struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev,
>>  {
>>  	return ERR_PTR(-ENODEV);
>>  }
>> +
>> +static inline struct extcon_dev *extcon_dev_allocate(const char **cables)
>> +{
>> +	return ERR_PTR(-ENOMEM);
>> +}
>> +
>> +static inline void extcon_dev_free(struct extcon_dev *edev) { }
>>  #endif /* CONFIG_EXTCON */
>>  #endif /* __LINUX_EXTCON_H__ */
>>
>>
>> here's full bisection log:
>>
>> git bisect start
>> # good: [a798c10faf62a505d24e5f6213fbaf904a39623f] Linux 3.15-rc2
>> git bisect good a798c10faf62a505d24e5f6213fbaf904a39623f
>> # bad: [3019b77470c1f10b23438917f73cad386e4f7f02] Merge branch 'extcon-next' of git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/extcon into merge
>> git bisect bad 3019b77470c1f10b23438917f73cad386e4f7f02
>> # bad: [f68f3aeb530b1efe3d6bf583db7a6255d15544eb] extcon: max14577: Use devm_extcon_dev_allocate for extcon_dev
>> git bisect bad f68f3aeb530b1efe3d6bf583db7a6255d15544eb
>> # good: [489096faca790b75653478d2f9d4774dd4f07b93] extcon: gpio: Use devm_extcon_dev_register()
>> git bisect good 489096faca790b75653478d2f9d4774dd4f07b93
>> # good: [5a451cded8793798e0d409e6ed6f8c53785ae929] extcon: arizona: Use devm_extcon_dev_register()
>> git bisect good 5a451cded8793798e0d409e6ed6f8c53785ae929
>> # bad: [cbe68e2d93df61fe40ddfea4d75f169fabadc155] extcon: Add devm_extcon_dev_allocate/free to manage the resource of extcon device
>> git bisect bad cbe68e2d93df61fe40ddfea4d75f169fabadc155
>> # bad: [854b85057cc6b90a326b731174b6c6dbbf34222a] extcon: Add extcon_dev_allocate/free() to control the memory of extcon device
>> git bisect bad 854b85057cc6b90a326b731174b6c6dbbf34222a
>> # first bad commit: [854b85057cc6b90a326b731174b6c6dbbf34222a] extcon: Add extcon_dev_allocate/free() to control the memory of extcon device
>>
>> And the bug is very simple and affects *all* users of extcon class,
>> which tells me that this big series switching over to devm_* resources
>> wasn't tested at all. Originally extcon_dev_register() was calling
>> device_register(&edev->dev) which will call device_initialize(dev)
>> followed by device_add(dev).
>>
>> After this commit, extcon_dev_register() now calls
>> device_add(&edev->dev) directly but never calls device_initialize()
>> anywhere. Was this *ever* tested anywhere ????? I suppose not!
>>
>> Please fix that up ASAP.
> 
> After fixing (actually, hacking) the first problem:
> 
> diff --git a/drivers/extcon/extcon-class.c b/drivers/extcon/extcon-class.c
> index 677c502..d1b74e8 100644
> --- a/drivers/extcon/extcon-class.c
> +++ b/drivers/extcon/extcon-class.c
> @@ -594,7 +594,7 @@ int extcon_dev_register(struct extcon_dev *edev)
>  	}
>  	dev_set_name(&edev->dev, "%s", edev->name);
>  
> -	ret = device_add(&edev->dev);
> +	ret = device_register(&edev->dev);

It is not bug.

As I comment on previous reply,
This patchset add 'extcon_dev_allocate()' to allocate the memory of
extcon device. So, extcon_dev_allocate() calls 'device_initialize("
before calling extcon_dev_register() and then extcon_dev_register()
calls device_add() function as following.

edev = extcon_dev_allocate()
	{
		...
		device_initialize(&edev->dev) (line.683)
	}

ret = extcon_dev_register(edev)
	{
		...
		device_add(&edev->dev);
		...
	}

>  	if (ret) {
>  		put_device(&edev->dev);
>  		return ret;
> 
> another problem shows up when connecting the USB cable:
> 
> [   99.386598] INFO: trying to register non-static key.
> [   99.391787] the code is fine but needs lockdep annotation.
> [   99.397529] turning off the locking correctness validator.
> [   99.403262] CPU: 1 PID: 757 Comm: irq/39-palmas Tainted: G        W     3.15.0-rc2-00041-g3019b77-dirty #315
> [   99.413552] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
> [   99.421658] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
> [   99.429216] [<c05426b4>] (dump_stack) from [<c0085584>] (__lock_acquire+0x17c8/0x1bc0)
> [   99.437498] [<c0085584>] (__lock_acquire) from [<c008617c>] (lock_acquire+0xa4/0x100)
> [   99.445692] [<c008617c>] (lock_acquire) from [<c05486e0>] (_raw_spin_lock_irqsave+0x38/0x4c)
> [   99.454530] [<c05486e0>] (_raw_spin_lock_irqsave) from [<c0462610>] (extcon_update_state+0x20/0x20c)
> [   99.464084] [<c0462610>] (extcon_update_state) from [<c0462f6c>] (palmas_vbus_irq_handler+0x60/0xa4)
> [   99.473640] [<c0462f6c>] (palmas_vbus_irq_handler) from [<c0091ce0>] (handle_nested_irq+0xa0/0x100)
> [   99.483109] [<c0091ce0>] (handle_nested_irq) from [<c0368e20>] (regmap_irq_thread+0x17c/0x300)
> [   99.492120] [<c0368e20>] (regmap_irq_thread) from [<c008ff20>] (irq_thread_fn+0x1c/0x40)
> [   99.500586] [<c008ff20>] (irq_thread_fn) from [<c0090238>] (irq_thread+0x12c/0x188)
> [   99.508600] [<c0090238>] (irq_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
> [   99.515882] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
> [   99.523534] palmas-usb palmas_usb.7: USB cable is attached
> 
> Again, another sign that this was not tested! That is caused by the same
> commit. It seems like you want *all* extcon users to call
> devm_extcon_dev_allocate() but you didn't fix palmas to do that, I
> suspect a few other drivers are missing that patch too.
> 
> Here's the change for palmas:
> 
> From: Felipe Balbi <balbi@ti.com>
> Subject: extcon: palmas: fix regression on extcon-next
> 
> All extcon users must rely on devm_extcon_dev_allocate() otherwise
> device registration will fail.
> 
> Signed-of-by: Felipe Balbi <balbi@ti.com>

I sent already following patch to use devm_extcon_dev_* function 
But, following patch didn't get ack or review message from mfd maintainer and author.
So, I have not yet to merge this patch on extcon-next branch
[1]
[PATCHv2 6/9] extcon: palmas: Use devm_extcon_dev_allocate for extcon_dev
- https://lkml.org/lkml/2014/4/21/162

If you possible, I'd like you to test this patch[1] based on extcon-next branch.

Thanks,
Chanwoo Choi

> ---
> 
> diff --git a/drivers/extcon/extcon-palmas.c b/drivers/extcon/extcon-palmas.c
> index 1a770e0..23a20d9 100644
> --- a/drivers/extcon/extcon-palmas.c
> +++ b/drivers/extcon/extcon-palmas.c
> @@ -57,7 +57,7 @@ static irqreturn_t palmas_vbus_irq_handler(int irq, void *_palmas_usb)
>  	if (vbus_line_state & PALMAS_INT3_LINE_STATE_VBUS) {
>  		if (palmas_usb->linkstat != PALMAS_USB_STATE_VBUS) {
>  			palmas_usb->linkstat = PALMAS_USB_STATE_VBUS;
> -			extcon_set_cable_state(&palmas_usb->edev, "USB", true);
> +			extcon_set_cable_state(palmas_usb->edev, "USB", true);
>  			dev_info(palmas_usb->dev, "USB cable is attached\n");
>  		} else {
>  			dev_dbg(palmas_usb->dev,
> @@ -66,7 +66,7 @@ static irqreturn_t palmas_vbus_irq_handler(int irq, void *_palmas_usb)
>  	} else if (!(vbus_line_state & PALMAS_INT3_LINE_STATE_VBUS)) {
>  		if (palmas_usb->linkstat == PALMAS_USB_STATE_VBUS) {
>  			palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
> -			extcon_set_cable_state(&palmas_usb->edev, "USB", false);
> +			extcon_set_cable_state(palmas_usb->edev, "USB", false);
>  			dev_info(palmas_usb->dev, "USB cable is detached\n");
>  		} else {
>  			dev_dbg(palmas_usb->dev,
> @@ -93,7 +93,7 @@ static irqreturn_t palmas_id_irq_handler(int irq, void *_palmas_usb)
>  			PALMAS_USB_ID_INT_LATCH_CLR,
>  			PALMAS_USB_ID_INT_EN_HI_CLR_ID_GND);
>  		palmas_usb->linkstat = PALMAS_USB_STATE_ID;
> -		extcon_set_cable_state(&palmas_usb->edev, "USB-HOST", true);
> +		extcon_set_cable_state(palmas_usb->edev, "USB-HOST", true);
>  		dev_info(palmas_usb->dev, "USB-HOST cable is attached\n");
>  	} else if ((set & PALMAS_USB_ID_INT_SRC_ID_FLOAT) &&
>  				(id_src & PALMAS_USB_ID_INT_SRC_ID_FLOAT)) {
> @@ -101,17 +101,17 @@ static irqreturn_t palmas_id_irq_handler(int irq, void *_palmas_usb)
>  			PALMAS_USB_ID_INT_LATCH_CLR,
>  			PALMAS_USB_ID_INT_EN_HI_CLR_ID_FLOAT);
>  		palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
> -		extcon_set_cable_state(&palmas_usb->edev, "USB-HOST", false);
> +		extcon_set_cable_state(palmas_usb->edev, "USB-HOST", false);
>  		dev_info(palmas_usb->dev, "USB-HOST cable is detached\n");
>  	} else if ((palmas_usb->linkstat == PALMAS_USB_STATE_ID) &&
>  				(!(set & PALMAS_USB_ID_INT_SRC_ID_GND))) {
>  		palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
> -		extcon_set_cable_state(&palmas_usb->edev, "USB-HOST", false);
> +		extcon_set_cable_state(palmas_usb->edev, "USB-HOST", false);
>  		dev_info(palmas_usb->dev, "USB-HOST cable is detached\n");
>  	} else if ((palmas_usb->linkstat == PALMAS_USB_STATE_DISCONNECT) &&
>  				(id_src & PALMAS_USB_ID_INT_SRC_ID_GND)) {
>  		palmas_usb->linkstat = PALMAS_USB_STATE_ID;
> -		extcon_set_cable_state(&palmas_usb->edev, "USB-HOST", true);
> +		extcon_set_cable_state(palmas_usb->edev, "USB-HOST", true);
>  		dev_info(palmas_usb->dev, " USB-HOST cable is attached\n");
>  	}
>  
> @@ -187,15 +187,19 @@ static int palmas_usb_probe(struct platform_device *pdev)
>  
>  	platform_set_drvdata(pdev, palmas_usb);
>  
> -	palmas_usb->edev.supported_cable = palmas_extcon_cable;
> -	palmas_usb->edev.dev.parent = palmas_usb->dev;
> -	palmas_usb->edev.name = kstrdup(node->name, GFP_KERNEL);
> -	palmas_usb->edev.mutually_exclusive = mutually_exclusive;
> +	palmas_usb->edev = devm_extcon_dev_allocate(&pdev->dev, palmas_extcon_cable);
> +	if (!palmas_usb->edev) {
> +		dev_err(&pdev->dev, "failed to allocate extcon_device\n");
> +		return -ENOMEM;
> +	}
> +	palmas_usb->edev->dev.parent = palmas_usb->dev;
> +	palmas_usb->edev->name = kstrdup(node->name, GFP_KERNEL);
> +	palmas_usb->edev->mutually_exclusive = mutually_exclusive;
>  
> -	status = devm_extcon_dev_register(&pdev->dev, &palmas_usb->edev);
> +	status = devm_extcon_dev_register(&pdev->dev, palmas_usb->edev);
>  	if (status) {
>  		dev_err(&pdev->dev, "failed to register extcon device\n");
> -		kfree(palmas_usb->edev.name);
> +		kfree(palmas_usb->edev->name);
>  		return status;
>  	}
>  
> @@ -209,7 +213,7 @@ static int palmas_usb_probe(struct platform_device *pdev)
>  		if (status < 0) {
>  			dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
>  					palmas_usb->id_irq, status);
> -			kfree(palmas_usb->edev.name);
> +			kfree(palmas_usb->edev->name);
>  			return status;
>  		}
>  	}
> @@ -224,7 +228,7 @@ static int palmas_usb_probe(struct platform_device *pdev)
>  		if (status < 0) {
>  			dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
>  					palmas_usb->vbus_irq, status);
> -			kfree(palmas_usb->edev.name);
> +			kfree(palmas_usb->edev->name);
>  			return status;
>  		}
>  	}
> @@ -238,7 +242,7 @@ static int palmas_usb_remove(struct platform_device *pdev)
>  {
>  	struct palmas_usb *palmas_usb = platform_get_drvdata(pdev);
>  
> -	kfree(palmas_usb->edev.name);
> +	kfree(palmas_usb->edev->name);
>  
>  	return 0;
>  }
> diff --git a/include/linux/mfd/palmas.h b/include/linux/mfd/palmas.h
> index 9974e38..b8f87b7 100644
> --- a/include/linux/mfd/palmas.h
> +++ b/include/linux/mfd/palmas.h
> @@ -415,7 +415,7 @@ struct palmas_usb {
>  	struct palmas *palmas;
>  	struct device *dev;
>  
> -	struct extcon_dev edev;
> +	struct extcon_dev *edev;
>  
>  	int id_otg_irq;
>  	int id_irq;
> 
> I tested this on OMAP5 but there's still *another* regression, it takes
> some 15 seconds for enumeration to happen after cable is attached:
> 
> [  126.476804] palmas-usb palmas_usb.7: USB cable is attached
> [  141.912688] g_mass_storage gadget: super-speed config #1: Linux File-Backed Storage
> 
> Dure, seriously ??? I'll continue debugging this, but god damn!!!!
> 
> cheers
> 

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Felipe Balbi April 24, 2014, 6:47 a.m. UTC | #2
Hi,

On Thu, Apr 24, 2014 at 02:35:44PM +0900, Chanwoo Choi wrote:
> Hi Felipe,
> 
> Thanks for your test and review.
> 
> On 04/24/2014 03:28 AM, Felipe Balbi wrote:
> > Hi,
> > 
> > On Wed, Apr 23, 2014 at 12:20:52PM -0500, Felipe Balbi wrote:
> >>> I've been testing extcon-next to make sure USB3 on OMAP5 will work out
> >>> of the box but I see a regression when I merge your tree on top of
> >>> v3.15-rc2 + Tony's DT fixes.
> >>>
> >>> Here's what I see (trimmed):
> >>>
> >>> [    1.805870] palmas 0-0048: Muxing GPIO 2, PWM 0, LED 0
> >>> [    1.812516] ------------[ cut here ]------------
> >>> [    1.817387] WARNING: CPU: 0 PID: 6 at include/linux/kref.h:47 kobject_get+0x64/0x78()
> >>> [    1.817691]  mmcblk0boot1: unknown partition table
> >>> [    1.830601] Modules linked in:
> >>> [    1.833827] CPU: 0 PID: 6 Comm: kworker/u4:0 Tainted: G        W     3.15.0-rc2-00041-g3019b77 #308
> >>> [    1.843333] Workqueue: deferwq deferred_probe_work_func
> >>> [    1.848728]  mmcblk0boot0: unknown partition table
> >>> [    1.853928] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
> >>> [    1.862086] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
> >>> [    1.869667] [<c05426b4>] (dump_stack) from [<c0040928>] (warn_slowpath_common+0x6c/0x90)
> >>> [    1.878181] [<c0040928>] (warn_slowpath_common) from [<c00409e8>] (warn_slowpath_null+0x1c/0x24)
> >>> [    1.887421] [<c00409e8>] (warn_slowpath_null) from [<c02d50c4>] (kobject_get+0x64/0x78)
> >>> [    1.895837] [<c02d50c4>] (kobject_get) from [<c0350188>] (device_add+0x18/0x520)
> >>> [    1.903629] [<c0350188>] (device_add) from [<c0462a5c>] (extcon_dev_register+0x48/0x104)
> >>> [    1.912145] [<c0462a5c>] (extcon_dev_register) from [<c0462b44>] (devm_extcon_dev_register+0x2c/0x68)
> >>> [    1.921847] [<c0462b44>] (devm_extcon_dev_register) from [<c04630c0>] (palmas_usb_probe+0x110/0x304)
> >>> [    1.931453] [<c04630c0>] (palmas_usb_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> >>> [    1.940333] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>> [    1.949664] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>> [    1.958634] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>> [    1.967003] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>> [    1.975387] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> >>> [    1.983678] [<c0350590>] (device_add) from [<c045a310>] (of_platform_device_create_pdata+0x6c/0x8c)
> >>> [    1.993155] [<c045a310>] (of_platform_device_create_pdata) from [<c045a418>] (of_platform_bus_create+0xdc/0x168)
> >>> [    2.003818] [<c045a418>] (of_platform_bus_create) from [<c045a5cc>] (of_platform_populate+0x5c/0xa0)
> >>> [    2.013399] [<c045a5cc>] (of_platform_populate) from [<c0373c78>] (palmas_i2c_probe+0x30c/0x584)
> >>> [    2.022606] [<c0373c78>] (palmas_i2c_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>> [    2.031722] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>> [    2.040715] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>> [    2.049098] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>> [    2.057482] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> >>> [    2.065774] [<c0350590>] (device_add) from [<c0424020>] (i2c_new_device+0x12c/0x18c)
> >>> [    2.073885] [<c0424020>] (i2c_new_device) from [<c0424980>] (i2c_register_adapter+0x278/0x498)
> >>> [    2.082903] [<c0424980>] (i2c_register_adapter) from [<c04275c0>] (omap_i2c_probe+0x4a4/0x6d0)
> >>> [    2.091925] [<c04275c0>] (omap_i2c_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> >>> [    2.100582] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>> [    2.109883] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>> [    2.118823] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>> [    2.127194] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>> [    2.135584] [<c035206c>] (bus_probe_device) from [<c03524ac>] (deferred_probe_work_func+0x64/0x94)
> >>> [    2.144975] [<c03524ac>] (deferred_probe_work_func) from [<c0058c70>] (process_one_work+0x1ac/0x4cc)
> >>> [    2.154545] [<c0058c70>] (process_one_work) from [<c0059b10>] (worker_thread+0x114/0x3b4)
> >>> [    2.163119] [<c0059b10>] (worker_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
> >>> [    2.170695] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
> >>> [    2.178259] ---[ end trace 3006de6450234d28 ]---
> >>> [    2.183081] kobject 'palmas_usb' (eca58c38): tried to add an uninitialized object, something is seriously wrong.
> >>> [    2.193731] CPU: 0 PID: 6 Comm: kworker/u4:0 Tainted: G        W     3.15.0-rc2-00041-g3019b77 #308
> >>> [    2.203201] Workqueue: deferwq deferred_probe_work_func
> >>> [    2.208687] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
> >>> [    2.216789] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
> >>> [    2.224357] [<c05426b4>] (dump_stack) from [<c02d5c28>] (kobject_add+0x88/0x98)
> >>> [    2.232014] [<c02d5c28>] (kobject_add) from [<c0350250>] (device_add+0xe0/0x520)
> >>> [    2.239758] [<c0350250>] (device_add) from [<c0462a5c>] (extcon_dev_register+0x48/0x104)
> >>> [    2.248235] [<c0462a5c>] (extcon_dev_register) from [<c0462b44>] (devm_extcon_dev_register+0x2c/0x68)
> >>> [    2.257901] [<c0462b44>] (devm_extcon_dev_register) from [<c04630c0>] (palmas_usb_probe+0x110/0x304)
> >>> [    2.267467] [<c04630c0>] (palmas_usb_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> >>> [    2.276298] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>> [    2.285591] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>> [    2.294520] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>> [    2.302905] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>> [    2.311286] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> >>> [    2.319583] [<c0350590>] (device_add) from [<c045a310>] (of_platform_device_create_pdata+0x6c/0x8c)
> >>> [    2.329063] [<c045a310>] (of_platform_device_create_pdata) from [<c045a418>] (of_platform_bus_create+0xdc/0x168)
> >>> [    2.339725] [<c045a418>] (of_platform_bus_create) from [<c045a5cc>] (of_platform_populate+0x5c/0xa0)
> >>> [    2.349296] [<c045a5cc>] (of_platform_populate) from [<c0373c78>] (palmas_i2c_probe+0x30c/0x584)
> >>> [    2.358496] [<c0373c78>] (palmas_i2c_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>> [    2.367609] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>> [    2.376523] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>> [    2.384914] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>> [    2.393301] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> >>> [    2.401601] [<c0350590>] (device_add) from [<c0424020>] (i2c_new_device+0x12c/0x18c)
> >>> [    2.409707] [<c0424020>] (i2c_new_device) from [<c0424980>] (i2c_register_adapter+0x278/0x498)
> >>> [    2.418727] [<c0424980>] (i2c_register_adapter) from [<c04275c0>] (omap_i2c_probe+0x4a4/0x6d0)
> >>> [    2.427741] [<c04275c0>] (omap_i2c_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> >>> [    2.436382] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>> [    2.445680] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>> [    2.454613] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>> [    2.463001] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>> [    2.471385] [<c035206c>] (bus_probe_device) from [<c03524ac>] (deferred_probe_work_func+0x64/0x94)
> >>> [    2.480772] [<c03524ac>] (deferred_probe_work_func) from [<c0058c70>] (process_one_work+0x1ac/0x4cc)
> >>> [    2.490339] [<c0058c70>] (process_one_work) from [<c0059b10>] (worker_thread+0x114/0x3b4)
> >>> [    2.498906] [<c0059b10>] (worker_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
> >>> [    2.506460] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
> >>> [    2.514023] ------------[ cut here ]------------
> >>> [    2.518870] WARNING: CPU: 0 PID: 6 at lib/kobject.c:670 kobject_put+0x80/0x90()
> >>> [    2.526514] kobject: 'palmas_usb' (eca58c38): is not initialized, yet kobject_put() is being called.
> >>> [    2.536076] Modules linked in:
> >>> [    2.539287] CPU: 0 PID: 6 Comm: kworker/u4:0 Tainted: G        W     3.15.0-rc2-00041-g3019b77 #308
> >>> [    2.548753] Workqueue: deferwq deferred_probe_work_func
> >>> [    2.554223] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
> >>> [    2.562341] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
> >>> [    2.569911] [<c05426b4>] (dump_stack) from [<c0040928>] (warn_slowpath_common+0x6c/0x90)
> >>> [    2.578391] [<c0040928>] (warn_slowpath_common) from [<c004097c>] (warn_slowpath_fmt+0x30/0x40)
> >>> [    2.587502] [<c004097c>] (warn_slowpath_fmt) from [<c02d5158>] (kobject_put+0x80/0x90)
> >>> [    2.595780] [<c02d5158>] (kobject_put) from [<c03502fc>] (device_add+0x18c/0x520)
> >>> [    2.603623] [<c03502fc>] (device_add) from [<c0462a5c>] (extcon_dev_register+0x48/0x104)
> >>> [    2.612103] [<c0462a5c>] (extcon_dev_register) from [<c0462b44>] (devm_extcon_dev_register+0x2c/0x68)
> >>> [    2.621762] [<c0462b44>] (devm_extcon_dev_register) from [<c04630c0>] (palmas_usb_probe+0x110/0x304)
> >>> [    2.631321] [<c04630c0>] (palmas_usb_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> >>> [    2.640161] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>> [    2.649447] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>> [    2.658386] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>> [    2.666757] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>> [    2.675144] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> >>> [    2.683441] [<c0350590>] (device_add) from [<c045a310>] (of_platform_device_create_pdata+0x6c/0x8c)
> >>> [    2.692921] [<c045a310>] (of_platform_device_create_pdata) from [<c045a418>] (of_platform_bus_create+0xdc/0x168)
> >>> [    2.703575] [<c045a418>] (of_platform_bus_create) from [<c045a5cc>] (of_platform_populate+0x5c/0xa0)
> >>> [    2.713139] [<c045a5cc>] (of_platform_populate) from [<c0373c78>] (palmas_i2c_probe+0x30c/0x584)
> >>> [    2.722341] [<c0373c78>] (palmas_i2c_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>> [    2.731457] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>> [    2.740380] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>> [    2.748764] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>> [    2.757135] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> >>> [    2.765429] [<c0350590>] (device_add) from [<c0424020>] (i2c_new_device+0x12c/0x18c)
> >>> [    2.773549] [<c0424020>] (i2c_new_device) from [<c0424980>] (i2c_register_adapter+0x278/0x498)
> >>> [    2.782576] [<c0424980>] (i2c_register_adapter) from [<c04275c0>] (omap_i2c_probe+0x4a4/0x6d0)
> >>> [    2.791597] [<c04275c0>] (omap_i2c_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> >>> [    2.800261] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>> [    2.809560] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>> [    2.818489] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>> [    2.826865] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>> [    2.835253] [<c035206c>] (bus_probe_device) from [<c03524ac>] (deferred_probe_work_func+0x64/0x94)
> >>> [    2.844637] [<c03524ac>] (deferred_probe_work_func) from [<c0058c70>] (process_one_work+0x1ac/0x4cc)
> >>> [    2.854205] [<c0058c70>] (process_one_work) from [<c0059b10>] (worker_thread+0x114/0x3b4)
> >>> [    2.862778] [<c0059b10>] (worker_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
> >>> [    2.870349] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
> >>> [    2.877911] ---[ end trace 3006de6450234d29 ]---
> >>> [    2.882734] ------------[ cut here ]------------
> >>> [    2.887573] WARNING: CPU: 0 PID: 6 at lib/kobject.c:670 kobject_put+0x80/0x90()
> >>> [    2.895209] kobject: 'palmas_usb' (eca58c38): is not initialized, yet kobject_put() is being called.
> >>> [    2.904765] Modules linked in:
> >>> [    2.907971] CPU: 0 PID: 6 Comm: kworker/u4:0 Tainted: G        W     3.15.0-rc2-00041-g3019b77 #308
> >>> [    2.917447] Workqueue: deferwq deferred_probe_work_func
> >>> [    2.922924] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
> >>> [    2.931033] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
> >>> [    2.938606] [<c05426b4>] (dump_stack) from [<c0040928>] (warn_slowpath_common+0x6c/0x90)
> >>> [    2.947069] [<c0040928>] (warn_slowpath_common) from [<c004097c>] (warn_slowpath_fmt+0x30/0x40)
> >>> [    2.956187] [<c004097c>] (warn_slowpath_fmt) from [<c02d5158>] (kobject_put+0x80/0x90)
> >>> [    2.964483] [<c02d5158>] (kobject_put) from [<c0462abc>] (extcon_dev_register+0xa8/0x104)
> >>> [    2.973053] [<c0462abc>] (extcon_dev_register) from [<c0462b44>] (devm_extcon_dev_register+0x2c/0x68)
> >>> [    2.982718] [<c0462b44>] (devm_extcon_dev_register) from [<c04630c0>] (palmas_usb_probe+0x110/0x304)
> >>> [    2.992285] [<c04630c0>] (palmas_usb_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> >>> [    3.001124] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>> [    3.010423] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>> [    3.019358] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>> [    3.027746] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>> [    3.036121] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> >>> [    3.044418] [<c0350590>] (device_add) from [<c045a310>] (of_platform_device_create_pdata+0x6c/0x8c)
> >>> [    3.053893] [<c045a310>] (of_platform_device_create_pdata) from [<c045a418>] (of_platform_bus_create+0xdc/0x168)
> >>> [    3.064550] [<c045a418>] (of_platform_bus_create) from [<c045a5cc>] (of_platform_populate+0x5c/0xa0)
> >>> [    3.074124] [<c045a5cc>] (of_platform_populate) from [<c0373c78>] (palmas_i2c_probe+0x30c/0x584)
> >>> [    3.083338] [<c0373c78>] (palmas_i2c_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>> [    3.092447] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>> [    3.101381] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>> [    3.109767] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>> [    3.118147] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> >>> [    3.126432] [<c0350590>] (device_add) from [<c0424020>] (i2c_new_device+0x12c/0x18c)
> >>> [    3.134547] [<c0424020>] (i2c_new_device) from [<c0424980>] (i2c_register_adapter+0x278/0x498)
> >>> [    3.143569] [<c0424980>] (i2c_register_adapter) from [<c04275c0>] (omap_i2c_probe+0x4a4/0x6d0)
> >>> [    3.152593] [<c04275c0>] (omap_i2c_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> >>> [    3.161249] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>> [    3.170537] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>> [    3.179472] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>> [    3.187854] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>> [    3.196222] [<c035206c>] (bus_probe_device) from [<c03524ac>] (deferred_probe_work_func+0x64/0x94)
> >>> [    3.205611] [<c03524ac>] (deferred_probe_work_func) from [<c0058c70>] (process_one_work+0x1ac/0x4cc)
> >>> [    3.215174] [<c0058c70>] (process_one_work) from [<c0059b10>] (worker_thread+0x114/0x3b4)
> >>> [    3.223739] [<c0059b10>] (worker_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
> >>> [    3.231313] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
> >>> [    3.238883] ---[ end trace 3006de6450234d2a ]---
> >>> [    3.243711] palmas-usb palmas_usb.7: failed to register extcon device
> >>> [    3.250493] palmas-usb: probe of palmas_usb.7 failed with error -22
> >>>
> >>> Any ideas ??
> >>
> >> bisected down to:
> >>
> >> commit 854b85057cc6b90a326b731174b6c6dbbf34222a
> >> Author: Chanwoo Choi <cw00.choi@samsung.com>
> >> Date:   Mon Apr 21 19:46:51 2014 +0900
> >>
> >>     extcon: Add extcon_dev_allocate/free() to control the memory of extcon device
> >>     
> >>     This patch add APIs to control the extcon device on extcon provider driver.
> >>     The extcon_dev_allocate() allocates the memory of extcon device and initializes
> >>     supported cables. And then extcon_dev_free() decrement the reference of the
> >>     device of extcon device and free the memory of the extcon device. This APIs
> >>     must need to implement devm_extcon_dev_allocate()/free() APIs.
> >>     
> >>     Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
> >>
> >> diff --git a/drivers/extcon/extcon-class.c b/drivers/extcon/extcon-class.c
> >> index f6df689..3e485bc 100644
> >> --- a/drivers/extcon/extcon-class.c
> >> +++ b/drivers/extcon/extcon-class.c
> >> @@ -558,6 +558,9 @@ static int create_extcon_class(void)
> >>  
> >>  static void extcon_dev_release(struct device *dev)
> >>  {
> >> +	struct extcon_dev *edev = dev_to_extcon_dev(dev);
> >> +
> >> +	kfree(edev);
> >>  }
> >>  
> >>  static const char *muex_name = "mutually_exclusive";
> >> @@ -576,7 +579,7 @@ static void dummy_sysfs_dev_release(struct device *dev)
> >>   */
> >>  int extcon_dev_register(struct extcon_dev *edev)
> >>  {
> >> -	int ret, index = 0;
> >> +	int ret;
> >>  
> >>  	if (!extcon_class) {
> >>  		ret = create_extcon_class();
> >> @@ -584,80 +587,150 @@ int extcon_dev_register(struct extcon_dev *edev)
> >>  			return ret;
> >>  	}
> >>  
> >> -	if (edev->supported_cable) {
> >> -		/* Get size of array */
> >> -		for (index = 0; edev->supported_cable[index]; index++)
> >> -			;
> >> -		edev->max_supported = index;
> >> -	} else {
> >> -		edev->max_supported = 0;
> >> +	edev->name = edev->name ? edev->name : dev_name(edev->dev.parent);
> >> +	if (IS_ERR_OR_NULL(edev->name)) {
> >> +		dev_err(&edev->dev, "extcon device name is null\n");
> >> +		return -EINVAL;
> >>  	}
> >> +	dev_set_name(&edev->dev, "%s", edev->name);
> >>  
> >> -	if (index > SUPPORTED_CABLE_MAX) {
> >> -		dev_err(&edev->dev, "extcon: maximum number of supported cables exceeded.\n");
> >> -		return -EINVAL;
> >> +	ret = device_add(&edev->dev);
> >> +	if (ret) {
> >> +		put_device(&edev->dev);
> >> +		return ret;
> >>  	}
> >> +#if defined(CONFIG_ANDROID)
> >> +	if (switch_class)
> >> +		ret = class_compat_create_link(switch_class, &edev->dev, NULL);
> >> +#endif /* CONFIG_ANDROID */
> >>  
> >> -	edev->dev.class = extcon_class;
> >> -	edev->dev.release = extcon_dev_release;
> >> +	RAW_INIT_NOTIFIER_HEAD(&edev->nh);
> >>  
> >> -	edev->name = edev->name ? edev->name : dev_name(edev->dev.parent);
> >> -	if (IS_ERR_OR_NULL(edev->name)) {
> >> -		dev_err(&edev->dev,
> >> -			"extcon device name is null\n");
> >> -		return -EINVAL;
> >> +	dev_set_drvdata(&edev->dev, edev);
> >> +	edev->state = 0;
> >> +
> >> +	mutex_lock(&extcon_dev_list_lock);
> >> +	list_add(&edev->entry, &extcon_dev_list);
> >> +	mutex_unlock(&extcon_dev_list_lock);
> >> +
> >> +	return 0;
> >> +}
> >> +EXPORT_SYMBOL_GPL(extcon_dev_register);
> >> +
> >> +/**
> >> + * extcon_dev_unregister() - Unregister the extcon device.
> >> + * @edev:	the extcon device instance to be unregistered.
> >> + */
> >> +void extcon_dev_unregister(struct extcon_dev *edev)
> >> +{
> >> +	mutex_lock(&extcon_dev_list_lock);
> >> +	list_del(&edev->entry);
> >> +	mutex_unlock(&extcon_dev_list_lock);
> >> +
> >> +	if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
> >> +		dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
> >> +				dev_name(&edev->dev));
> >> +		return;
> >>  	}
> >> -	dev_set_name(&edev->dev, "%s", edev->name);
> >>  
> >> -	if (edev->max_supported) {
> >> -		char buf[10];
> >> -		char *str;
> >> -		struct extcon_cable *cable;
> >> +	device_unregister(&edev->dev);
> >>  
> >> -		edev->cables = kzalloc(sizeof(struct extcon_cable) *
> >> -				       edev->max_supported, GFP_KERNEL);
> >> -		if (!edev->cables) {
> >> +#if defined(CONFIG_ANDROID)
> >> +	if (switch_class)
> >> +		class_compat_remove_link(switch_class, &edev->dev, NULL);
> >> +#endif
> >> +}
> >> +EXPORT_SYMBOL_GPL(extcon_dev_unregister);
> >> +
> >> +/*
> >> + * extcon_dev_allocate() - Allocate the memory of extcon device.
> >> + * @supported_cable:	Array of supported cable names ending with NULL.
> >> + *			If supported_cable is NULL, cable name related APIs
> >> + *			are disabled.
> >> + *
> >> + * This function allocates the memory for extcon device without allocating
> >> + * memory in each extcon provider driver and initialize default setting for
> >> + * extcon device.
> >> + *
> >> + * Return the pointer of extcon device if success or ERR_PTR(err) if fail
> >> + */
> >> +struct extcon_dev *extcon_dev_allocate(const char **supported_cable)
> >> +{
> >> +	struct extcon_dev *edev;
> >> +	int index, ret, count = 0;
> >> +
> >> +	edev = kzalloc(sizeof(*edev), GFP_KERNEL);
> >> +	if (!edev) {
> >> +		pr_err("Failed to allocate the memory for extcon device\n");
> >> +		return ERR_PTR(-ENOMEM);
> >> +	}
> >> +
> >> +	edev->max_supported = 0;
> >> +	edev->supported_cable = supported_cable;
> >> +	if (edev->supported_cable) {
> >> +		for (count = 0; edev->supported_cable[count]; count++)
> >> +			;
> >> +		edev->max_supported = count;
> >> +		if (count > SUPPORTED_CABLE_MAX) {
> >> +			pr_err("Exceed max number of supported cables\n");
> >>  			ret = -ENOMEM;
> >> -			goto err_sysfs_alloc;
> >> +			goto err;
> >>  		}
> >> -		for (index = 0; index < edev->max_supported; index++) {
> >> -			cable = &edev->cables[index];
> >> +	}
> >>  
> >> -			snprintf(buf, 10, "cable.%d", index);
> >> -			str = kzalloc(sizeof(char) * (strlen(buf) + 1),
> >> -				      GFP_KERNEL);
> >> -			if (!str) {
> >> -				for (index--; index >= 0; index--) {
> >> -					cable = &edev->cables[index];
> >> -					kfree(cable->attr_g.name);
> >> -				}
> >> -				ret = -ENOMEM;
> >> +	edev->dev.class = extcon_class;
> >> +	edev->dev.release = extcon_dev_release;
> >> +	device_initialize(&edev->dev);
> >> +	spin_lock_init(&edev->lock);
> >> +
> >> +	if (!edev->max_supported)
> >> +		return 0;
> >> +
> >> +	edev->cables = kzalloc(sizeof(struct extcon_cable) *
> >> +			       edev->max_supported, GFP_KERNEL);
> >> +	if (!edev->cables) {
> >> +		ret = -ENOMEM;
> >> +		goto err;
> >> +	}
> >>  
> >> -				goto err_alloc_cables;
> >> +	for (index = 0; index < edev->max_supported; index++) {
> >> +		struct extcon_cable *cable = &edev->cables[index];
> >> +		char buf[10];
> >> +		char *str;
> >> +
> >> +		snprintf(buf, 10, "cable.%d", index);
> >> +		str = kzalloc(sizeof(char) * (strlen(buf) + 1),
> >> +			      GFP_KERNEL);
> >> +		if (!str) {
> >> +			for (index--; index >= 0; index--) {
> >> +				cable = &edev->cables[index];
> >> +				kfree(cable->attr_g.name);
> >>  			}
> >> -			strcpy(str, buf);
> >> -
> >> -			cable->edev = edev;
> >> -			cable->cable_index = index;
> >> -			cable->attrs[0] = &cable->attr_name.attr;
> >> -			cable->attrs[1] = &cable->attr_state.attr;
> >> -			cable->attrs[2] = NULL;
> >> -			cable->attr_g.name = str;
> >> -			cable->attr_g.attrs = cable->attrs;
> >> -
> >> -			sysfs_attr_init(&cable->attr_name.attr);
> >> -			cable->attr_name.attr.name = "name";
> >> -			cable->attr_name.attr.mode = 0444;
> >> -			cable->attr_name.show = cable_name_show;
> >> -
> >> -			sysfs_attr_init(&cable->attr_state.attr);
> >> -			cable->attr_state.attr.name = "state";
> >> -			cable->attr_state.attr.mode = 0444;
> >> -			cable->attr_state.show = cable_state_show;
> >> +			ret = -ENOMEM;
> >> +			goto err_alloc_cables;
> >>  		}
> >> +		strcpy(str, buf);
> >> +
> >> +		cable->edev = edev;
> >> +		cable->cable_index = index;
> >> +		cable->attrs[0] = &cable->attr_name.attr;
> >> +		cable->attrs[1] = &cable->attr_state.attr;
> >> +		cable->attrs[2] = NULL;
> >> +		cable->attr_g.name = str;
> >> +		cable->attr_g.attrs = cable->attrs;
> >> +
> >> +		sysfs_attr_init(&cable->attr_name.attr);
> >> +		cable->attr_name.attr.name = "name";
> >> +		cable->attr_name.attr.mode = 0444;
> >> +		cable->attr_name.show = cable_name_show;
> >> +
> >> +		sysfs_attr_init(&cable->attr_state.attr);
> >> +		cable->attr_state.attr.name = "state";
> >> +		cable->attr_state.attr.mode = 0444;
> >> +		cable->attr_state.show = cable_state_show;
> >>  	}
> >>  
> >> -	if (edev->max_supported && edev->mutually_exclusive) {
> >> +	if (edev->mutually_exclusive) {
> >>  		char buf[80];
> >>  		char *name;
> >>  
> >> @@ -703,59 +776,32 @@ int extcon_dev_register(struct extcon_dev *edev)
> >>  		}
> >>  		edev->attr_g_muex.name = muex_name;
> >>  		edev->attr_g_muex.attrs = edev->attrs_muex;
> >> -
> >>  	}
> >>  
> >> -	if (edev->max_supported) {
> >> -		edev->extcon_dev_type.groups =
> >> -			kzalloc(sizeof(struct attribute_group *) *
> >> -				(edev->max_supported + 2), GFP_KERNEL);
> >> -		if (!edev->extcon_dev_type.groups) {
> >> -			ret = -ENOMEM;
> >> -			goto err_alloc_groups;
> >> -		}
> >> -
> >> -		edev->extcon_dev_type.name = dev_name(&edev->dev);
> >> -		edev->extcon_dev_type.release = dummy_sysfs_dev_release;
> >> -
> >> -		for (index = 0; index < edev->max_supported; index++)
> >> -			edev->extcon_dev_type.groups[index] =
> >> -				&edev->cables[index].attr_g;
> >> -		if (edev->mutually_exclusive)
> >> -			edev->extcon_dev_type.groups[index] =
> >> -				&edev->attr_g_muex;
> >> -
> >> -		edev->dev.type = &edev->extcon_dev_type;
> >> +	edev->extcon_dev_type.groups =
> >> +		kzalloc(sizeof(struct attribute_group *) *
> >> +			(edev->max_supported + 2), GFP_KERNEL);
> >> +	if (!edev->extcon_dev_type.groups) {
> >> +		ret = -ENOMEM;
> >> +		goto err_alloc_groups;
> >>  	}
> >>  
> >> -	ret = device_register(&edev->dev);
> >> -	if (ret) {
> >> -		put_device(&edev->dev);
> >> -		goto err_dev;
> >> -	}
> >> -#if defined(CONFIG_ANDROID)
> >> -	if (switch_class)
> >> -		ret = class_compat_create_link(switch_class, &edev->dev, NULL);
> >> -#endif /* CONFIG_ANDROID */
> >> -
> >> -	spin_lock_init(&edev->lock);
> >> -
> >> -	RAW_INIT_NOTIFIER_HEAD(&edev->nh);
> >> +	edev->extcon_dev_type.name = dev_name(&edev->dev);
> >> +	edev->extcon_dev_type.release = dummy_sysfs_dev_release;
> >>  
> >> -	dev_set_drvdata(&edev->dev, edev);
> >> -	edev->state = 0;
> >> +	for (index = 0; index < edev->max_supported; index++)
> >> +		edev->extcon_dev_type.groups[index] =
> >> +			&edev->cables[index].attr_g;
> >> +	if (edev->mutually_exclusive)
> >> +		edev->extcon_dev_type.groups[index] =
> >> +			&edev->attr_g_muex;
> >>  
> >> -	mutex_lock(&extcon_dev_list_lock);
> >> -	list_add(&edev->entry, &extcon_dev_list);
> >> -	mutex_unlock(&extcon_dev_list_lock);
> >> +	edev->dev.type = &edev->extcon_dev_type;
> >>  
> >> -	return 0;
> >> +	return edev;
> >>  
> >> -err_dev:
> >> -	if (edev->max_supported)
> >> -		kfree(edev->extcon_dev_type.groups);
> >>  err_alloc_groups:
> >> -	if (edev->max_supported && edev->mutually_exclusive) {
> >> +	if (edev->mutually_exclusive) {
> >>  		for (index = 0; edev->mutually_exclusive[index]; index++)
> >>  			kfree(edev->d_attrs_muex[index].attr.name);
> >>  		kfree(edev->d_attrs_muex);
> >> @@ -765,36 +811,22 @@ err_muex:
> >>  	for (index = 0; index < edev->max_supported; index++)
> >>  		kfree(edev->cables[index].attr_g.name);
> >>  err_alloc_cables:
> >> -	if (edev->max_supported)
> >> -		kfree(edev->cables);
> >> -err_sysfs_alloc:
> >> -	return ret;
> >> +	kfree(edev->cables);
> >> +err:
> >> +	kfree(edev);
> >> +
> >> +	return ERR_PTR(ret);
> >>  }
> >> -EXPORT_SYMBOL_GPL(extcon_dev_register);
> >> +EXPORT_SYMBOL_GPL(extcon_dev_allocate);
> >>  
> >> -/**
> >> - * extcon_dev_unregister() - Unregister the extcon device.
> >> - * @edev:	the extcon device instance to be unregistered.
> >> - *
> >> - * Note that this does not call kfree(edev) because edev was not allocated
> >> - * by this class.
> >> +/*
> >> + * extcon_dev_free() - Free the memory of extcon device.
> >> + * @edev:	the extcon device to free
> >>   */
> >> -void extcon_dev_unregister(struct extcon_dev *edev)
> >> +void extcon_dev_free(struct extcon_dev *edev)
> >>  {
> >>  	int index;
> >>  
> >> -	mutex_lock(&extcon_dev_list_lock);
> >> -	list_del(&edev->entry);
> >> -	mutex_unlock(&extcon_dev_list_lock);
> >> -
> >> -	if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
> >> -		dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
> >> -				dev_name(&edev->dev));
> >> -		return;
> >> -	}
> >> -
> >> -	device_unregister(&edev->dev);
> >> -
> >>  	if (edev->mutually_exclusive && edev->max_supported) {
> >>  		for (index = 0; edev->mutually_exclusive[index];
> >>  				index++)
> >> @@ -811,13 +843,10 @@ void extcon_dev_unregister(struct extcon_dev *edev)
> >>  		kfree(edev->cables);
> >>  	}
> >>  
> >> -#if defined(CONFIG_ANDROID)
> >> -	if (switch_class)
> >> -		class_compat_remove_link(switch_class, &edev->dev, NULL);
> >> -#endif
> >> -	put_device(&edev->dev);
> >> +	if (edev)
> >> +		put_device(&edev->dev);
> >>  }
> >> -EXPORT_SYMBOL_GPL(extcon_dev_unregister);
> >> +EXPORT_SYMBOL_GPL(extcon_dev_free);
> >>  
> >>  static void devm_extcon_dev_unreg(struct device *dev, void *res)
> >>  {
> >> diff --git a/include/linux/extcon.h b/include/linux/extcon.h
> >> index 85a8a5b..20587ee 100644
> >> --- a/include/linux/extcon.h
> >> +++ b/include/linux/extcon.h
> >> @@ -179,6 +179,8 @@ struct extcon_specific_cable_nb {
> >>  
> >>  #if IS_ENABLED(CONFIG_EXTCON)
> >>  
> >> +#define dev_to_extcon_dev(d) container_of(d, struct extcon_dev, dev)
> >> +
> >>  /*
> >>   * Following APIs are for notifiers or configurations.
> >>   * Notifiers are the external port and connection devices.
> >> @@ -250,6 +252,12 @@ extern int extcon_unregister_notifier(struct extcon_dev *edev,
> >>  				      struct notifier_block *nb);
> >>  
> >>  /*
> >> + * Following APIs control the memory of extcon device.
> >> + */
> >> +extern struct extcon_dev *extcon_dev_allocate(const char **cables);
> >> +extern void extcon_dev_free(struct extcon_dev *edev);
> >> +
> >> +/*
> >>   * Following API get the extcon device from devicetree.
> >>   * This function use phandle of devicetree to get extcon device directly.
> >>   */
> >> @@ -353,5 +361,12 @@ static inline struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev,
> >>  {
> >>  	return ERR_PTR(-ENODEV);
> >>  }
> >> +
> >> +static inline struct extcon_dev *extcon_dev_allocate(const char **cables)
> >> +{
> >> +	return ERR_PTR(-ENOMEM);
> >> +}
> >> +
> >> +static inline void extcon_dev_free(struct extcon_dev *edev) { }
> >>  #endif /* CONFIG_EXTCON */
> >>  #endif /* __LINUX_EXTCON_H__ */
> >>
> >>
> >> here's full bisection log:
> >>
> >> git bisect start
> >> # good: [a798c10faf62a505d24e5f6213fbaf904a39623f] Linux 3.15-rc2
> >> git bisect good a798c10faf62a505d24e5f6213fbaf904a39623f
> >> # bad: [3019b77470c1f10b23438917f73cad386e4f7f02] Merge branch 'extcon-next' of git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/extcon into merge
> >> git bisect bad 3019b77470c1f10b23438917f73cad386e4f7f02
> >> # bad: [f68f3aeb530b1efe3d6bf583db7a6255d15544eb] extcon: max14577: Use devm_extcon_dev_allocate for extcon_dev
> >> git bisect bad f68f3aeb530b1efe3d6bf583db7a6255d15544eb
> >> # good: [489096faca790b75653478d2f9d4774dd4f07b93] extcon: gpio: Use devm_extcon_dev_register()
> >> git bisect good 489096faca790b75653478d2f9d4774dd4f07b93
> >> # good: [5a451cded8793798e0d409e6ed6f8c53785ae929] extcon: arizona: Use devm_extcon_dev_register()
> >> git bisect good 5a451cded8793798e0d409e6ed6f8c53785ae929
> >> # bad: [cbe68e2d93df61fe40ddfea4d75f169fabadc155] extcon: Add devm_extcon_dev_allocate/free to manage the resource of extcon device
> >> git bisect bad cbe68e2d93df61fe40ddfea4d75f169fabadc155
> >> # bad: [854b85057cc6b90a326b731174b6c6dbbf34222a] extcon: Add extcon_dev_allocate/free() to control the memory of extcon device
> >> git bisect bad 854b85057cc6b90a326b731174b6c6dbbf34222a
> >> # first bad commit: [854b85057cc6b90a326b731174b6c6dbbf34222a] extcon: Add extcon_dev_allocate/free() to control the memory of extcon device
> >>
> >> And the bug is very simple and affects *all* users of extcon class,
> >> which tells me that this big series switching over to devm_* resources
> >> wasn't tested at all. Originally extcon_dev_register() was calling
> >> device_register(&edev->dev) which will call device_initialize(dev)
> >> followed by device_add(dev).
> >>
> >> After this commit, extcon_dev_register() now calls
> >> device_add(&edev->dev) directly but never calls device_initialize()
> >> anywhere. Was this *ever* tested anywhere ????? I suppose not!
> >>
> >> Please fix that up ASAP.
> > 
> > After fixing (actually, hacking) the first problem:
> > 
> > diff --git a/drivers/extcon/extcon-class.c b/drivers/extcon/extcon-class.c
> > index 677c502..d1b74e8 100644
> > --- a/drivers/extcon/extcon-class.c
> > +++ b/drivers/extcon/extcon-class.c
> > @@ -594,7 +594,7 @@ int extcon_dev_register(struct extcon_dev *edev)
> >  	}
> >  	dev_set_name(&edev->dev, "%s", edev->name);
> >  
> > -	ret = device_add(&edev->dev);
> > +	ret = device_register(&edev->dev);
> 
> It is not bug.
> 
> As I comment on previous reply,
> This patchset add 'extcon_dev_allocate()' to allocate the memory of
> extcon device. So, extcon_dev_allocate() calls 'device_initialize("
> before calling extcon_dev_register() and then extcon_dev_register()
> calls device_add() function as following.
> 
> edev = extcon_dev_allocate()
> 	{
> 		...
> 		device_initialize(&edev->dev) (line.683)
> 	}
> 
> ret = extcon_dev_register(edev)
> 	{
> 		...
> 		device_add(&edev->dev);
> 		...
> 	}
> 
> >  	if (ret) {
> >  		put_device(&edev->dev);
> >  		return ret;
> > 
> > another problem shows up when connecting the USB cable:
> > 
> > [   99.386598] INFO: trying to register non-static key.
> > [   99.391787] the code is fine but needs lockdep annotation.
> > [   99.397529] turning off the locking correctness validator.
> > [   99.403262] CPU: 1 PID: 757 Comm: irq/39-palmas Tainted: G        W     3.15.0-rc2-00041-g3019b77-dirty #315
> > [   99.413552] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
> > [   99.421658] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
> > [   99.429216] [<c05426b4>] (dump_stack) from [<c0085584>] (__lock_acquire+0x17c8/0x1bc0)
> > [   99.437498] [<c0085584>] (__lock_acquire) from [<c008617c>] (lock_acquire+0xa4/0x100)
> > [   99.445692] [<c008617c>] (lock_acquire) from [<c05486e0>] (_raw_spin_lock_irqsave+0x38/0x4c)
> > [   99.454530] [<c05486e0>] (_raw_spin_lock_irqsave) from [<c0462610>] (extcon_update_state+0x20/0x20c)
> > [   99.464084] [<c0462610>] (extcon_update_state) from [<c0462f6c>] (palmas_vbus_irq_handler+0x60/0xa4)
> > [   99.473640] [<c0462f6c>] (palmas_vbus_irq_handler) from [<c0091ce0>] (handle_nested_irq+0xa0/0x100)
> > [   99.483109] [<c0091ce0>] (handle_nested_irq) from [<c0368e20>] (regmap_irq_thread+0x17c/0x300)
> > [   99.492120] [<c0368e20>] (regmap_irq_thread) from [<c008ff20>] (irq_thread_fn+0x1c/0x40)
> > [   99.500586] [<c008ff20>] (irq_thread_fn) from [<c0090238>] (irq_thread+0x12c/0x188)
> > [   99.508600] [<c0090238>] (irq_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
> > [   99.515882] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
> > [   99.523534] palmas-usb palmas_usb.7: USB cable is attached
> > 
> > Again, another sign that this was not tested! That is caused by the same
> > commit. It seems like you want *all* extcon users to call
> > devm_extcon_dev_allocate() but you didn't fix palmas to do that, I
> > suspect a few other drivers are missing that patch too.
> > 
> > Here's the change for palmas:
> > 
> > From: Felipe Balbi <balbi@ti.com>
> > Subject: extcon: palmas: fix regression on extcon-next
> > 
> > All extcon users must rely on devm_extcon_dev_allocate() otherwise
> > device registration will fail.
> > 
> > Signed-of-by: Felipe Balbi <balbi@ti.com>
> 
> I sent already following patch to use devm_extcon_dev_* function 
> But, following patch didn't get ack or review message from mfd maintainer and author.
> So, I have not yet to merge this patch on extcon-next branch
> [1]
> [PATCHv2 6/9] extcon: palmas: Use devm_extcon_dev_allocate for extcon_dev
> - https://lkml.org/lkml/2014/4/21/162
> 
> If you possible, I'd like you to test this patch[1] based on extcon-next branch.

I'll do that. I can't seem to find that patch in my inbox even though
I'm in Cc.

One thing though, the current order of your next branch will create a
non-bisectable history, you need to shuffle things around to avoid this
not working spots.
Chanwoo Choi April 24, 2014, 8:13 a.m. UTC | #3
Hi,

On 04/24/2014 03:47 PM, Felipe Balbi wrote:
> Hi,
> 
> On Thu, Apr 24, 2014 at 02:35:44PM +0900, Chanwoo Choi wrote:
>> Hi Felipe,
>>
>> Thanks for your test and review.
>>
>> On 04/24/2014 03:28 AM, Felipe Balbi wrote:
>>> Hi,
>>>
>>> On Wed, Apr 23, 2014 at 12:20:52PM -0500, Felipe Balbi wrote:
>>>>> I've been testing extcon-next to make sure USB3 on OMAP5 will work out
>>>>> of the box but I see a regression when I merge your tree on top of
>>>>> v3.15-rc2 + Tony's DT fixes.
>>>>>
>>>>> Here's what I see (trimmed):
>>>>>
>>>>> [    1.805870] palmas 0-0048: Muxing GPIO 2, PWM 0, LED 0
>>>>> [    1.812516] ------------[ cut here ]------------
>>>>> [    1.817387] WARNING: CPU: 0 PID: 6 at include/linux/kref.h:47 kobject_get+0x64/0x78()
>>>>> [    1.817691]  mmcblk0boot1: unknown partition table
>>>>> [    1.830601] Modules linked in:
>>>>> [    1.833827] CPU: 0 PID: 6 Comm: kworker/u4:0 Tainted: G        W     3.15.0-rc2-00041-g3019b77 #308
>>>>> [    1.843333] Workqueue: deferwq deferred_probe_work_func
>>>>> [    1.848728]  mmcblk0boot0: unknown partition table
>>>>> [    1.853928] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
>>>>> [    1.862086] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
>>>>> [    1.869667] [<c05426b4>] (dump_stack) from [<c0040928>] (warn_slowpath_common+0x6c/0x90)
>>>>> [    1.878181] [<c0040928>] (warn_slowpath_common) from [<c00409e8>] (warn_slowpath_null+0x1c/0x24)
>>>>> [    1.887421] [<c00409e8>] (warn_slowpath_null) from [<c02d50c4>] (kobject_get+0x64/0x78)
>>>>> [    1.895837] [<c02d50c4>] (kobject_get) from [<c0350188>] (device_add+0x18/0x520)
>>>>> [    1.903629] [<c0350188>] (device_add) from [<c0462a5c>] (extcon_dev_register+0x48/0x104)
>>>>> [    1.912145] [<c0462a5c>] (extcon_dev_register) from [<c0462b44>] (devm_extcon_dev_register+0x2c/0x68)
>>>>> [    1.921847] [<c0462b44>] (devm_extcon_dev_register) from [<c04630c0>] (palmas_usb_probe+0x110/0x304)
>>>>> [    1.931453] [<c04630c0>] (palmas_usb_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
>>>>> [    1.940333] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>>>> [    1.949664] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>>>> [    1.958634] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>>>> [    1.967003] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>>>> [    1.975387] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
>>>>> [    1.983678] [<c0350590>] (device_add) from [<c045a310>] (of_platform_device_create_pdata+0x6c/0x8c)
>>>>> [    1.993155] [<c045a310>] (of_platform_device_create_pdata) from [<c045a418>] (of_platform_bus_create+0xdc/0x168)
>>>>> [    2.003818] [<c045a418>] (of_platform_bus_create) from [<c045a5cc>] (of_platform_populate+0x5c/0xa0)
>>>>> [    2.013399] [<c045a5cc>] (of_platform_populate) from [<c0373c78>] (palmas_i2c_probe+0x30c/0x584)
>>>>> [    2.022606] [<c0373c78>] (palmas_i2c_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>>>> [    2.031722] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>>>> [    2.040715] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>>>> [    2.049098] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>>>> [    2.057482] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
>>>>> [    2.065774] [<c0350590>] (device_add) from [<c0424020>] (i2c_new_device+0x12c/0x18c)
>>>>> [    2.073885] [<c0424020>] (i2c_new_device) from [<c0424980>] (i2c_register_adapter+0x278/0x498)
>>>>> [    2.082903] [<c0424980>] (i2c_register_adapter) from [<c04275c0>] (omap_i2c_probe+0x4a4/0x6d0)
>>>>> [    2.091925] [<c04275c0>] (omap_i2c_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
>>>>> [    2.100582] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>>>> [    2.109883] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>>>> [    2.118823] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>>>> [    2.127194] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>>>> [    2.135584] [<c035206c>] (bus_probe_device) from [<c03524ac>] (deferred_probe_work_func+0x64/0x94)
>>>>> [    2.144975] [<c03524ac>] (deferred_probe_work_func) from [<c0058c70>] (process_one_work+0x1ac/0x4cc)
>>>>> [    2.154545] [<c0058c70>] (process_one_work) from [<c0059b10>] (worker_thread+0x114/0x3b4)
>>>>> [    2.163119] [<c0059b10>] (worker_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
>>>>> [    2.170695] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
>>>>> [    2.178259] ---[ end trace 3006de6450234d28 ]---
>>>>> [    2.183081] kobject 'palmas_usb' (eca58c38): tried to add an uninitialized object, something is seriously wrong.
>>>>> [    2.193731] CPU: 0 PID: 6 Comm: kworker/u4:0 Tainted: G        W     3.15.0-rc2-00041-g3019b77 #308
>>>>> [    2.203201] Workqueue: deferwq deferred_probe_work_func
>>>>> [    2.208687] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
>>>>> [    2.216789] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
>>>>> [    2.224357] [<c05426b4>] (dump_stack) from [<c02d5c28>] (kobject_add+0x88/0x98)
>>>>> [    2.232014] [<c02d5c28>] (kobject_add) from [<c0350250>] (device_add+0xe0/0x520)
>>>>> [    2.239758] [<c0350250>] (device_add) from [<c0462a5c>] (extcon_dev_register+0x48/0x104)
>>>>> [    2.248235] [<c0462a5c>] (extcon_dev_register) from [<c0462b44>] (devm_extcon_dev_register+0x2c/0x68)
>>>>> [    2.257901] [<c0462b44>] (devm_extcon_dev_register) from [<c04630c0>] (palmas_usb_probe+0x110/0x304)
>>>>> [    2.267467] [<c04630c0>] (palmas_usb_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
>>>>> [    2.276298] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>>>> [    2.285591] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>>>> [    2.294520] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>>>> [    2.302905] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>>>> [    2.311286] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
>>>>> [    2.319583] [<c0350590>] (device_add) from [<c045a310>] (of_platform_device_create_pdata+0x6c/0x8c)
>>>>> [    2.329063] [<c045a310>] (of_platform_device_create_pdata) from [<c045a418>] (of_platform_bus_create+0xdc/0x168)
>>>>> [    2.339725] [<c045a418>] (of_platform_bus_create) from [<c045a5cc>] (of_platform_populate+0x5c/0xa0)
>>>>> [    2.349296] [<c045a5cc>] (of_platform_populate) from [<c0373c78>] (palmas_i2c_probe+0x30c/0x584)
>>>>> [    2.358496] [<c0373c78>] (palmas_i2c_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>>>> [    2.367609] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>>>> [    2.376523] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>>>> [    2.384914] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>>>> [    2.393301] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
>>>>> [    2.401601] [<c0350590>] (device_add) from [<c0424020>] (i2c_new_device+0x12c/0x18c)
>>>>> [    2.409707] [<c0424020>] (i2c_new_device) from [<c0424980>] (i2c_register_adapter+0x278/0x498)
>>>>> [    2.418727] [<c0424980>] (i2c_register_adapter) from [<c04275c0>] (omap_i2c_probe+0x4a4/0x6d0)
>>>>> [    2.427741] [<c04275c0>] (omap_i2c_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
>>>>> [    2.436382] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>>>> [    2.445680] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>>>> [    2.454613] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>>>> [    2.463001] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>>>> [    2.471385] [<c035206c>] (bus_probe_device) from [<c03524ac>] (deferred_probe_work_func+0x64/0x94)
>>>>> [    2.480772] [<c03524ac>] (deferred_probe_work_func) from [<c0058c70>] (process_one_work+0x1ac/0x4cc)
>>>>> [    2.490339] [<c0058c70>] (process_one_work) from [<c0059b10>] (worker_thread+0x114/0x3b4)
>>>>> [    2.498906] [<c0059b10>] (worker_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
>>>>> [    2.506460] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
>>>>> [    2.514023] ------------[ cut here ]------------
>>>>> [    2.518870] WARNING: CPU: 0 PID: 6 at lib/kobject.c:670 kobject_put+0x80/0x90()
>>>>> [    2.526514] kobject: 'palmas_usb' (eca58c38): is not initialized, yet kobject_put() is being called.
>>>>> [    2.536076] Modules linked in:
>>>>> [    2.539287] CPU: 0 PID: 6 Comm: kworker/u4:0 Tainted: G        W     3.15.0-rc2-00041-g3019b77 #308
>>>>> [    2.548753] Workqueue: deferwq deferred_probe_work_func
>>>>> [    2.554223] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
>>>>> [    2.562341] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
>>>>> [    2.569911] [<c05426b4>] (dump_stack) from [<c0040928>] (warn_slowpath_common+0x6c/0x90)
>>>>> [    2.578391] [<c0040928>] (warn_slowpath_common) from [<c004097c>] (warn_slowpath_fmt+0x30/0x40)
>>>>> [    2.587502] [<c004097c>] (warn_slowpath_fmt) from [<c02d5158>] (kobject_put+0x80/0x90)
>>>>> [    2.595780] [<c02d5158>] (kobject_put) from [<c03502fc>] (device_add+0x18c/0x520)
>>>>> [    2.603623] [<c03502fc>] (device_add) from [<c0462a5c>] (extcon_dev_register+0x48/0x104)
>>>>> [    2.612103] [<c0462a5c>] (extcon_dev_register) from [<c0462b44>] (devm_extcon_dev_register+0x2c/0x68)
>>>>> [    2.621762] [<c0462b44>] (devm_extcon_dev_register) from [<c04630c0>] (palmas_usb_probe+0x110/0x304)
>>>>> [    2.631321] [<c04630c0>] (palmas_usb_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
>>>>> [    2.640161] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>>>> [    2.649447] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>>>> [    2.658386] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>>>> [    2.666757] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>>>> [    2.675144] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
>>>>> [    2.683441] [<c0350590>] (device_add) from [<c045a310>] (of_platform_device_create_pdata+0x6c/0x8c)
>>>>> [    2.692921] [<c045a310>] (of_platform_device_create_pdata) from [<c045a418>] (of_platform_bus_create+0xdc/0x168)
>>>>> [    2.703575] [<c045a418>] (of_platform_bus_create) from [<c045a5cc>] (of_platform_populate+0x5c/0xa0)
>>>>> [    2.713139] [<c045a5cc>] (of_platform_populate) from [<c0373c78>] (palmas_i2c_probe+0x30c/0x584)
>>>>> [    2.722341] [<c0373c78>] (palmas_i2c_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>>>> [    2.731457] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>>>> [    2.740380] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>>>> [    2.748764] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>>>> [    2.757135] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
>>>>> [    2.765429] [<c0350590>] (device_add) from [<c0424020>] (i2c_new_device+0x12c/0x18c)
>>>>> [    2.773549] [<c0424020>] (i2c_new_device) from [<c0424980>] (i2c_register_adapter+0x278/0x498)
>>>>> [    2.782576] [<c0424980>] (i2c_register_adapter) from [<c04275c0>] (omap_i2c_probe+0x4a4/0x6d0)
>>>>> [    2.791597] [<c04275c0>] (omap_i2c_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
>>>>> [    2.800261] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>>>> [    2.809560] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>>>> [    2.818489] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>>>> [    2.826865] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>>>> [    2.835253] [<c035206c>] (bus_probe_device) from [<c03524ac>] (deferred_probe_work_func+0x64/0x94)
>>>>> [    2.844637] [<c03524ac>] (deferred_probe_work_func) from [<c0058c70>] (process_one_work+0x1ac/0x4cc)
>>>>> [    2.854205] [<c0058c70>] (process_one_work) from [<c0059b10>] (worker_thread+0x114/0x3b4)
>>>>> [    2.862778] [<c0059b10>] (worker_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
>>>>> [    2.870349] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
>>>>> [    2.877911] ---[ end trace 3006de6450234d29 ]---
>>>>> [    2.882734] ------------[ cut here ]------------
>>>>> [    2.887573] WARNING: CPU: 0 PID: 6 at lib/kobject.c:670 kobject_put+0x80/0x90()
>>>>> [    2.895209] kobject: 'palmas_usb' (eca58c38): is not initialized, yet kobject_put() is being called.
>>>>> [    2.904765] Modules linked in:
>>>>> [    2.907971] CPU: 0 PID: 6 Comm: kworker/u4:0 Tainted: G        W     3.15.0-rc2-00041-g3019b77 #308
>>>>> [    2.917447] Workqueue: deferwq deferred_probe_work_func
>>>>> [    2.922924] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
>>>>> [    2.931033] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
>>>>> [    2.938606] [<c05426b4>] (dump_stack) from [<c0040928>] (warn_slowpath_common+0x6c/0x90)
>>>>> [    2.947069] [<c0040928>] (warn_slowpath_common) from [<c004097c>] (warn_slowpath_fmt+0x30/0x40)
>>>>> [    2.956187] [<c004097c>] (warn_slowpath_fmt) from [<c02d5158>] (kobject_put+0x80/0x90)
>>>>> [    2.964483] [<c02d5158>] (kobject_put) from [<c0462abc>] (extcon_dev_register+0xa8/0x104)
>>>>> [    2.973053] [<c0462abc>] (extcon_dev_register) from [<c0462b44>] (devm_extcon_dev_register+0x2c/0x68)
>>>>> [    2.982718] [<c0462b44>] (devm_extcon_dev_register) from [<c04630c0>] (palmas_usb_probe+0x110/0x304)
>>>>> [    2.992285] [<c04630c0>] (palmas_usb_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
>>>>> [    3.001124] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>>>> [    3.010423] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>>>> [    3.019358] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>>>> [    3.027746] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>>>> [    3.036121] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
>>>>> [    3.044418] [<c0350590>] (device_add) from [<c045a310>] (of_platform_device_create_pdata+0x6c/0x8c)
>>>>> [    3.053893] [<c045a310>] (of_platform_device_create_pdata) from [<c045a418>] (of_platform_bus_create+0xdc/0x168)
>>>>> [    3.064550] [<c045a418>] (of_platform_bus_create) from [<c045a5cc>] (of_platform_populate+0x5c/0xa0)
>>>>> [    3.074124] [<c045a5cc>] (of_platform_populate) from [<c0373c78>] (palmas_i2c_probe+0x30c/0x584)
>>>>> [    3.083338] [<c0373c78>] (palmas_i2c_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>>>> [    3.092447] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>>>> [    3.101381] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>>>> [    3.109767] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>>>> [    3.118147] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
>>>>> [    3.126432] [<c0350590>] (device_add) from [<c0424020>] (i2c_new_device+0x12c/0x18c)
>>>>> [    3.134547] [<c0424020>] (i2c_new_device) from [<c0424980>] (i2c_register_adapter+0x278/0x498)
>>>>> [    3.143569] [<c0424980>] (i2c_register_adapter) from [<c04275c0>] (omap_i2c_probe+0x4a4/0x6d0)
>>>>> [    3.152593] [<c04275c0>] (omap_i2c_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
>>>>> [    3.161249] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
>>>>> [    3.170537] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
>>>>> [    3.179472] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
>>>>> [    3.187854] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
>>>>> [    3.196222] [<c035206c>] (bus_probe_device) from [<c03524ac>] (deferred_probe_work_func+0x64/0x94)
>>>>> [    3.205611] [<c03524ac>] (deferred_probe_work_func) from [<c0058c70>] (process_one_work+0x1ac/0x4cc)
>>>>> [    3.215174] [<c0058c70>] (process_one_work) from [<c0059b10>] (worker_thread+0x114/0x3b4)
>>>>> [    3.223739] [<c0059b10>] (worker_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
>>>>> [    3.231313] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
>>>>> [    3.238883] ---[ end trace 3006de6450234d2a ]---
>>>>> [    3.243711] palmas-usb palmas_usb.7: failed to register extcon device
>>>>> [    3.250493] palmas-usb: probe of palmas_usb.7 failed with error -22
>>>>>
>>>>> Any ideas ??
>>>>
>>>> bisected down to:
>>>>
>>>> commit 854b85057cc6b90a326b731174b6c6dbbf34222a
>>>> Author: Chanwoo Choi <cw00.choi@samsung.com>
>>>> Date:   Mon Apr 21 19:46:51 2014 +0900
>>>>
>>>>     extcon: Add extcon_dev_allocate/free() to control the memory of extcon device
>>>>     
>>>>     This patch add APIs to control the extcon device on extcon provider driver.
>>>>     The extcon_dev_allocate() allocates the memory of extcon device and initializes
>>>>     supported cables. And then extcon_dev_free() decrement the reference of the
>>>>     device of extcon device and free the memory of the extcon device. This APIs
>>>>     must need to implement devm_extcon_dev_allocate()/free() APIs.
>>>>     
>>>>     Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
>>>>
>>>> diff --git a/drivers/extcon/extcon-class.c b/drivers/extcon/extcon-class.c
>>>> index f6df689..3e485bc 100644
>>>> --- a/drivers/extcon/extcon-class.c
>>>> +++ b/drivers/extcon/extcon-class.c
>>>> @@ -558,6 +558,9 @@ static int create_extcon_class(void)
>>>>  
>>>>  static void extcon_dev_release(struct device *dev)
>>>>  {
>>>> +	struct extcon_dev *edev = dev_to_extcon_dev(dev);
>>>> +
>>>> +	kfree(edev);
>>>>  }
>>>>  
>>>>  static const char *muex_name = "mutually_exclusive";
>>>> @@ -576,7 +579,7 @@ static void dummy_sysfs_dev_release(struct device *dev)
>>>>   */
>>>>  int extcon_dev_register(struct extcon_dev *edev)
>>>>  {
>>>> -	int ret, index = 0;
>>>> +	int ret;
>>>>  
>>>>  	if (!extcon_class) {
>>>>  		ret = create_extcon_class();
>>>> @@ -584,80 +587,150 @@ int extcon_dev_register(struct extcon_dev *edev)
>>>>  			return ret;
>>>>  	}
>>>>  
>>>> -	if (edev->supported_cable) {
>>>> -		/* Get size of array */
>>>> -		for (index = 0; edev->supported_cable[index]; index++)
>>>> -			;
>>>> -		edev->max_supported = index;
>>>> -	} else {
>>>> -		edev->max_supported = 0;
>>>> +	edev->name = edev->name ? edev->name : dev_name(edev->dev.parent);
>>>> +	if (IS_ERR_OR_NULL(edev->name)) {
>>>> +		dev_err(&edev->dev, "extcon device name is null\n");
>>>> +		return -EINVAL;
>>>>  	}
>>>> +	dev_set_name(&edev->dev, "%s", edev->name);
>>>>  
>>>> -	if (index > SUPPORTED_CABLE_MAX) {
>>>> -		dev_err(&edev->dev, "extcon: maximum number of supported cables exceeded.\n");
>>>> -		return -EINVAL;
>>>> +	ret = device_add(&edev->dev);
>>>> +	if (ret) {
>>>> +		put_device(&edev->dev);
>>>> +		return ret;
>>>>  	}
>>>> +#if defined(CONFIG_ANDROID)
>>>> +	if (switch_class)
>>>> +		ret = class_compat_create_link(switch_class, &edev->dev, NULL);
>>>> +#endif /* CONFIG_ANDROID */
>>>>  
>>>> -	edev->dev.class = extcon_class;
>>>> -	edev->dev.release = extcon_dev_release;
>>>> +	RAW_INIT_NOTIFIER_HEAD(&edev->nh);
>>>>  
>>>> -	edev->name = edev->name ? edev->name : dev_name(edev->dev.parent);
>>>> -	if (IS_ERR_OR_NULL(edev->name)) {
>>>> -		dev_err(&edev->dev,
>>>> -			"extcon device name is null\n");
>>>> -		return -EINVAL;
>>>> +	dev_set_drvdata(&edev->dev, edev);
>>>> +	edev->state = 0;
>>>> +
>>>> +	mutex_lock(&extcon_dev_list_lock);
>>>> +	list_add(&edev->entry, &extcon_dev_list);
>>>> +	mutex_unlock(&extcon_dev_list_lock);
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(extcon_dev_register);
>>>> +
>>>> +/**
>>>> + * extcon_dev_unregister() - Unregister the extcon device.
>>>> + * @edev:	the extcon device instance to be unregistered.
>>>> + */
>>>> +void extcon_dev_unregister(struct extcon_dev *edev)
>>>> +{
>>>> +	mutex_lock(&extcon_dev_list_lock);
>>>> +	list_del(&edev->entry);
>>>> +	mutex_unlock(&extcon_dev_list_lock);
>>>> +
>>>> +	if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
>>>> +		dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
>>>> +				dev_name(&edev->dev));
>>>> +		return;
>>>>  	}
>>>> -	dev_set_name(&edev->dev, "%s", edev->name);
>>>>  
>>>> -	if (edev->max_supported) {
>>>> -		char buf[10];
>>>> -		char *str;
>>>> -		struct extcon_cable *cable;
>>>> +	device_unregister(&edev->dev);
>>>>  
>>>> -		edev->cables = kzalloc(sizeof(struct extcon_cable) *
>>>> -				       edev->max_supported, GFP_KERNEL);
>>>> -		if (!edev->cables) {
>>>> +#if defined(CONFIG_ANDROID)
>>>> +	if (switch_class)
>>>> +		class_compat_remove_link(switch_class, &edev->dev, NULL);
>>>> +#endif
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(extcon_dev_unregister);
>>>> +
>>>> +/*
>>>> + * extcon_dev_allocate() - Allocate the memory of extcon device.
>>>> + * @supported_cable:	Array of supported cable names ending with NULL.
>>>> + *			If supported_cable is NULL, cable name related APIs
>>>> + *			are disabled.
>>>> + *
>>>> + * This function allocates the memory for extcon device without allocating
>>>> + * memory in each extcon provider driver and initialize default setting for
>>>> + * extcon device.
>>>> + *
>>>> + * Return the pointer of extcon device if success or ERR_PTR(err) if fail
>>>> + */
>>>> +struct extcon_dev *extcon_dev_allocate(const char **supported_cable)
>>>> +{
>>>> +	struct extcon_dev *edev;
>>>> +	int index, ret, count = 0;
>>>> +
>>>> +	edev = kzalloc(sizeof(*edev), GFP_KERNEL);
>>>> +	if (!edev) {
>>>> +		pr_err("Failed to allocate the memory for extcon device\n");
>>>> +		return ERR_PTR(-ENOMEM);
>>>> +	}
>>>> +
>>>> +	edev->max_supported = 0;
>>>> +	edev->supported_cable = supported_cable;
>>>> +	if (edev->supported_cable) {
>>>> +		for (count = 0; edev->supported_cable[count]; count++)
>>>> +			;
>>>> +		edev->max_supported = count;
>>>> +		if (count > SUPPORTED_CABLE_MAX) {
>>>> +			pr_err("Exceed max number of supported cables\n");
>>>>  			ret = -ENOMEM;
>>>> -			goto err_sysfs_alloc;
>>>> +			goto err;
>>>>  		}
>>>> -		for (index = 0; index < edev->max_supported; index++) {
>>>> -			cable = &edev->cables[index];
>>>> +	}
>>>>  
>>>> -			snprintf(buf, 10, "cable.%d", index);
>>>> -			str = kzalloc(sizeof(char) * (strlen(buf) + 1),
>>>> -				      GFP_KERNEL);
>>>> -			if (!str) {
>>>> -				for (index--; index >= 0; index--) {
>>>> -					cable = &edev->cables[index];
>>>> -					kfree(cable->attr_g.name);
>>>> -				}
>>>> -				ret = -ENOMEM;
>>>> +	edev->dev.class = extcon_class;
>>>> +	edev->dev.release = extcon_dev_release;
>>>> +	device_initialize(&edev->dev);
>>>> +	spin_lock_init(&edev->lock);
>>>> +
>>>> +	if (!edev->max_supported)
>>>> +		return 0;
>>>> +
>>>> +	edev->cables = kzalloc(sizeof(struct extcon_cable) *
>>>> +			       edev->max_supported, GFP_KERNEL);
>>>> +	if (!edev->cables) {
>>>> +		ret = -ENOMEM;
>>>> +		goto err;
>>>> +	}
>>>>  
>>>> -				goto err_alloc_cables;
>>>> +	for (index = 0; index < edev->max_supported; index++) {
>>>> +		struct extcon_cable *cable = &edev->cables[index];
>>>> +		char buf[10];
>>>> +		char *str;
>>>> +
>>>> +		snprintf(buf, 10, "cable.%d", index);
>>>> +		str = kzalloc(sizeof(char) * (strlen(buf) + 1),
>>>> +			      GFP_KERNEL);
>>>> +		if (!str) {
>>>> +			for (index--; index >= 0; index--) {
>>>> +				cable = &edev->cables[index];
>>>> +				kfree(cable->attr_g.name);
>>>>  			}
>>>> -			strcpy(str, buf);
>>>> -
>>>> -			cable->edev = edev;
>>>> -			cable->cable_index = index;
>>>> -			cable->attrs[0] = &cable->attr_name.attr;
>>>> -			cable->attrs[1] = &cable->attr_state.attr;
>>>> -			cable->attrs[2] = NULL;
>>>> -			cable->attr_g.name = str;
>>>> -			cable->attr_g.attrs = cable->attrs;
>>>> -
>>>> -			sysfs_attr_init(&cable->attr_name.attr);
>>>> -			cable->attr_name.attr.name = "name";
>>>> -			cable->attr_name.attr.mode = 0444;
>>>> -			cable->attr_name.show = cable_name_show;
>>>> -
>>>> -			sysfs_attr_init(&cable->attr_state.attr);
>>>> -			cable->attr_state.attr.name = "state";
>>>> -			cable->attr_state.attr.mode = 0444;
>>>> -			cable->attr_state.show = cable_state_show;
>>>> +			ret = -ENOMEM;
>>>> +			goto err_alloc_cables;
>>>>  		}
>>>> +		strcpy(str, buf);
>>>> +
>>>> +		cable->edev = edev;
>>>> +		cable->cable_index = index;
>>>> +		cable->attrs[0] = &cable->attr_name.attr;
>>>> +		cable->attrs[1] = &cable->attr_state.attr;
>>>> +		cable->attrs[2] = NULL;
>>>> +		cable->attr_g.name = str;
>>>> +		cable->attr_g.attrs = cable->attrs;
>>>> +
>>>> +		sysfs_attr_init(&cable->attr_name.attr);
>>>> +		cable->attr_name.attr.name = "name";
>>>> +		cable->attr_name.attr.mode = 0444;
>>>> +		cable->attr_name.show = cable_name_show;
>>>> +
>>>> +		sysfs_attr_init(&cable->attr_state.attr);
>>>> +		cable->attr_state.attr.name = "state";
>>>> +		cable->attr_state.attr.mode = 0444;
>>>> +		cable->attr_state.show = cable_state_show;
>>>>  	}
>>>>  
>>>> -	if (edev->max_supported && edev->mutually_exclusive) {
>>>> +	if (edev->mutually_exclusive) {
>>>>  		char buf[80];
>>>>  		char *name;
>>>>  
>>>> @@ -703,59 +776,32 @@ int extcon_dev_register(struct extcon_dev *edev)
>>>>  		}
>>>>  		edev->attr_g_muex.name = muex_name;
>>>>  		edev->attr_g_muex.attrs = edev->attrs_muex;
>>>> -
>>>>  	}
>>>>  
>>>> -	if (edev->max_supported) {
>>>> -		edev->extcon_dev_type.groups =
>>>> -			kzalloc(sizeof(struct attribute_group *) *
>>>> -				(edev->max_supported + 2), GFP_KERNEL);
>>>> -		if (!edev->extcon_dev_type.groups) {
>>>> -			ret = -ENOMEM;
>>>> -			goto err_alloc_groups;
>>>> -		}
>>>> -
>>>> -		edev->extcon_dev_type.name = dev_name(&edev->dev);
>>>> -		edev->extcon_dev_type.release = dummy_sysfs_dev_release;
>>>> -
>>>> -		for (index = 0; index < edev->max_supported; index++)
>>>> -			edev->extcon_dev_type.groups[index] =
>>>> -				&edev->cables[index].attr_g;
>>>> -		if (edev->mutually_exclusive)
>>>> -			edev->extcon_dev_type.groups[index] =
>>>> -				&edev->attr_g_muex;
>>>> -
>>>> -		edev->dev.type = &edev->extcon_dev_type;
>>>> +	edev->extcon_dev_type.groups =
>>>> +		kzalloc(sizeof(struct attribute_group *) *
>>>> +			(edev->max_supported + 2), GFP_KERNEL);
>>>> +	if (!edev->extcon_dev_type.groups) {
>>>> +		ret = -ENOMEM;
>>>> +		goto err_alloc_groups;
>>>>  	}
>>>>  
>>>> -	ret = device_register(&edev->dev);
>>>> -	if (ret) {
>>>> -		put_device(&edev->dev);
>>>> -		goto err_dev;
>>>> -	}
>>>> -#if defined(CONFIG_ANDROID)
>>>> -	if (switch_class)
>>>> -		ret = class_compat_create_link(switch_class, &edev->dev, NULL);
>>>> -#endif /* CONFIG_ANDROID */
>>>> -
>>>> -	spin_lock_init(&edev->lock);
>>>> -
>>>> -	RAW_INIT_NOTIFIER_HEAD(&edev->nh);
>>>> +	edev->extcon_dev_type.name = dev_name(&edev->dev);
>>>> +	edev->extcon_dev_type.release = dummy_sysfs_dev_release;
>>>>  
>>>> -	dev_set_drvdata(&edev->dev, edev);
>>>> -	edev->state = 0;
>>>> +	for (index = 0; index < edev->max_supported; index++)
>>>> +		edev->extcon_dev_type.groups[index] =
>>>> +			&edev->cables[index].attr_g;
>>>> +	if (edev->mutually_exclusive)
>>>> +		edev->extcon_dev_type.groups[index] =
>>>> +			&edev->attr_g_muex;
>>>>  
>>>> -	mutex_lock(&extcon_dev_list_lock);
>>>> -	list_add(&edev->entry, &extcon_dev_list);
>>>> -	mutex_unlock(&extcon_dev_list_lock);
>>>> +	edev->dev.type = &edev->extcon_dev_type;
>>>>  
>>>> -	return 0;
>>>> +	return edev;
>>>>  
>>>> -err_dev:
>>>> -	if (edev->max_supported)
>>>> -		kfree(edev->extcon_dev_type.groups);
>>>>  err_alloc_groups:
>>>> -	if (edev->max_supported && edev->mutually_exclusive) {
>>>> +	if (edev->mutually_exclusive) {
>>>>  		for (index = 0; edev->mutually_exclusive[index]; index++)
>>>>  			kfree(edev->d_attrs_muex[index].attr.name);
>>>>  		kfree(edev->d_attrs_muex);
>>>> @@ -765,36 +811,22 @@ err_muex:
>>>>  	for (index = 0; index < edev->max_supported; index++)
>>>>  		kfree(edev->cables[index].attr_g.name);
>>>>  err_alloc_cables:
>>>> -	if (edev->max_supported)
>>>> -		kfree(edev->cables);
>>>> -err_sysfs_alloc:
>>>> -	return ret;
>>>> +	kfree(edev->cables);
>>>> +err:
>>>> +	kfree(edev);
>>>> +
>>>> +	return ERR_PTR(ret);
>>>>  }
>>>> -EXPORT_SYMBOL_GPL(extcon_dev_register);
>>>> +EXPORT_SYMBOL_GPL(extcon_dev_allocate);
>>>>  
>>>> -/**
>>>> - * extcon_dev_unregister() - Unregister the extcon device.
>>>> - * @edev:	the extcon device instance to be unregistered.
>>>> - *
>>>> - * Note that this does not call kfree(edev) because edev was not allocated
>>>> - * by this class.
>>>> +/*
>>>> + * extcon_dev_free() - Free the memory of extcon device.
>>>> + * @edev:	the extcon device to free
>>>>   */
>>>> -void extcon_dev_unregister(struct extcon_dev *edev)
>>>> +void extcon_dev_free(struct extcon_dev *edev)
>>>>  {
>>>>  	int index;
>>>>  
>>>> -	mutex_lock(&extcon_dev_list_lock);
>>>> -	list_del(&edev->entry);
>>>> -	mutex_unlock(&extcon_dev_list_lock);
>>>> -
>>>> -	if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
>>>> -		dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
>>>> -				dev_name(&edev->dev));
>>>> -		return;
>>>> -	}
>>>> -
>>>> -	device_unregister(&edev->dev);
>>>> -
>>>>  	if (edev->mutually_exclusive && edev->max_supported) {
>>>>  		for (index = 0; edev->mutually_exclusive[index];
>>>>  				index++)
>>>> @@ -811,13 +843,10 @@ void extcon_dev_unregister(struct extcon_dev *edev)
>>>>  		kfree(edev->cables);
>>>>  	}
>>>>  
>>>> -#if defined(CONFIG_ANDROID)
>>>> -	if (switch_class)
>>>> -		class_compat_remove_link(switch_class, &edev->dev, NULL);
>>>> -#endif
>>>> -	put_device(&edev->dev);
>>>> +	if (edev)
>>>> +		put_device(&edev->dev);
>>>>  }
>>>> -EXPORT_SYMBOL_GPL(extcon_dev_unregister);
>>>> +EXPORT_SYMBOL_GPL(extcon_dev_free);
>>>>  
>>>>  static void devm_extcon_dev_unreg(struct device *dev, void *res)
>>>>  {
>>>> diff --git a/include/linux/extcon.h b/include/linux/extcon.h
>>>> index 85a8a5b..20587ee 100644
>>>> --- a/include/linux/extcon.h
>>>> +++ b/include/linux/extcon.h
>>>> @@ -179,6 +179,8 @@ struct extcon_specific_cable_nb {
>>>>  
>>>>  #if IS_ENABLED(CONFIG_EXTCON)
>>>>  
>>>> +#define dev_to_extcon_dev(d) container_of(d, struct extcon_dev, dev)
>>>> +
>>>>  /*
>>>>   * Following APIs are for notifiers or configurations.
>>>>   * Notifiers are the external port and connection devices.
>>>> @@ -250,6 +252,12 @@ extern int extcon_unregister_notifier(struct extcon_dev *edev,
>>>>  				      struct notifier_block *nb);
>>>>  
>>>>  /*
>>>> + * Following APIs control the memory of extcon device.
>>>> + */
>>>> +extern struct extcon_dev *extcon_dev_allocate(const char **cables);
>>>> +extern void extcon_dev_free(struct extcon_dev *edev);
>>>> +
>>>> +/*
>>>>   * Following API get the extcon device from devicetree.
>>>>   * This function use phandle of devicetree to get extcon device directly.
>>>>   */
>>>> @@ -353,5 +361,12 @@ static inline struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev,
>>>>  {
>>>>  	return ERR_PTR(-ENODEV);
>>>>  }
>>>> +
>>>> +static inline struct extcon_dev *extcon_dev_allocate(const char **cables)
>>>> +{
>>>> +	return ERR_PTR(-ENOMEM);
>>>> +}
>>>> +
>>>> +static inline void extcon_dev_free(struct extcon_dev *edev) { }
>>>>  #endif /* CONFIG_EXTCON */
>>>>  #endif /* __LINUX_EXTCON_H__ */
>>>>
>>>>
>>>> here's full bisection log:
>>>>
>>>> git bisect start
>>>> # good: [a798c10faf62a505d24e5f6213fbaf904a39623f] Linux 3.15-rc2
>>>> git bisect good a798c10faf62a505d24e5f6213fbaf904a39623f
>>>> # bad: [3019b77470c1f10b23438917f73cad386e4f7f02] Merge branch 'extcon-next' of git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/extcon into merge
>>>> git bisect bad 3019b77470c1f10b23438917f73cad386e4f7f02
>>>> # bad: [f68f3aeb530b1efe3d6bf583db7a6255d15544eb] extcon: max14577: Use devm_extcon_dev_allocate for extcon_dev
>>>> git bisect bad f68f3aeb530b1efe3d6bf583db7a6255d15544eb
>>>> # good: [489096faca790b75653478d2f9d4774dd4f07b93] extcon: gpio: Use devm_extcon_dev_register()
>>>> git bisect good 489096faca790b75653478d2f9d4774dd4f07b93
>>>> # good: [5a451cded8793798e0d409e6ed6f8c53785ae929] extcon: arizona: Use devm_extcon_dev_register()
>>>> git bisect good 5a451cded8793798e0d409e6ed6f8c53785ae929
>>>> # bad: [cbe68e2d93df61fe40ddfea4d75f169fabadc155] extcon: Add devm_extcon_dev_allocate/free to manage the resource of extcon device
>>>> git bisect bad cbe68e2d93df61fe40ddfea4d75f169fabadc155
>>>> # bad: [854b85057cc6b90a326b731174b6c6dbbf34222a] extcon: Add extcon_dev_allocate/free() to control the memory of extcon device
>>>> git bisect bad 854b85057cc6b90a326b731174b6c6dbbf34222a
>>>> # first bad commit: [854b85057cc6b90a326b731174b6c6dbbf34222a] extcon: Add extcon_dev_allocate/free() to control the memory of extcon device
>>>>
>>>> And the bug is very simple and affects *all* users of extcon class,
>>>> which tells me that this big series switching over to devm_* resources
>>>> wasn't tested at all. Originally extcon_dev_register() was calling
>>>> device_register(&edev->dev) which will call device_initialize(dev)
>>>> followed by device_add(dev).
>>>>
>>>> After this commit, extcon_dev_register() now calls
>>>> device_add(&edev->dev) directly but never calls device_initialize()
>>>> anywhere. Was this *ever* tested anywhere ????? I suppose not!
>>>>
>>>> Please fix that up ASAP.
>>>
>>> After fixing (actually, hacking) the first problem:
>>>
>>> diff --git a/drivers/extcon/extcon-class.c b/drivers/extcon/extcon-class.c
>>> index 677c502..d1b74e8 100644
>>> --- a/drivers/extcon/extcon-class.c
>>> +++ b/drivers/extcon/extcon-class.c
>>> @@ -594,7 +594,7 @@ int extcon_dev_register(struct extcon_dev *edev)
>>>  	}
>>>  	dev_set_name(&edev->dev, "%s", edev->name);
>>>  
>>> -	ret = device_add(&edev->dev);
>>> +	ret = device_register(&edev->dev);
>>
>> It is not bug.
>>
>> As I comment on previous reply,
>> This patchset add 'extcon_dev_allocate()' to allocate the memory of
>> extcon device. So, extcon_dev_allocate() calls 'device_initialize("
>> before calling extcon_dev_register() and then extcon_dev_register()
>> calls device_add() function as following.
>>
>> edev = extcon_dev_allocate()
>> 	{
>> 		...
>> 		device_initialize(&edev->dev) (line.683)
>> 	}
>>
>> ret = extcon_dev_register(edev)
>> 	{
>> 		...
>> 		device_add(&edev->dev);
>> 		...
>> 	}
>>
>>>  	if (ret) {
>>>  		put_device(&edev->dev);
>>>  		return ret;
>>>
>>> another problem shows up when connecting the USB cable:
>>>
>>> [   99.386598] INFO: trying to register non-static key.
>>> [   99.391787] the code is fine but needs lockdep annotation.
>>> [   99.397529] turning off the locking correctness validator.
>>> [   99.403262] CPU: 1 PID: 757 Comm: irq/39-palmas Tainted: G        W     3.15.0-rc2-00041-g3019b77-dirty #315
>>> [   99.413552] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
>>> [   99.421658] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
>>> [   99.429216] [<c05426b4>] (dump_stack) from [<c0085584>] (__lock_acquire+0x17c8/0x1bc0)
>>> [   99.437498] [<c0085584>] (__lock_acquire) from [<c008617c>] (lock_acquire+0xa4/0x100)
>>> [   99.445692] [<c008617c>] (lock_acquire) from [<c05486e0>] (_raw_spin_lock_irqsave+0x38/0x4c)
>>> [   99.454530] [<c05486e0>] (_raw_spin_lock_irqsave) from [<c0462610>] (extcon_update_state+0x20/0x20c)
>>> [   99.464084] [<c0462610>] (extcon_update_state) from [<c0462f6c>] (palmas_vbus_irq_handler+0x60/0xa4)
>>> [   99.473640] [<c0462f6c>] (palmas_vbus_irq_handler) from [<c0091ce0>] (handle_nested_irq+0xa0/0x100)
>>> [   99.483109] [<c0091ce0>] (handle_nested_irq) from [<c0368e20>] (regmap_irq_thread+0x17c/0x300)
>>> [   99.492120] [<c0368e20>] (regmap_irq_thread) from [<c008ff20>] (irq_thread_fn+0x1c/0x40)
>>> [   99.500586] [<c008ff20>] (irq_thread_fn) from [<c0090238>] (irq_thread+0x12c/0x188)
>>> [   99.508600] [<c0090238>] (irq_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
>>> [   99.515882] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
>>> [   99.523534] palmas-usb palmas_usb.7: USB cable is attached
>>>
>>> Again, another sign that this was not tested! That is caused by the same
>>> commit. It seems like you want *all* extcon users to call
>>> devm_extcon_dev_allocate() but you didn't fix palmas to do that, I
>>> suspect a few other drivers are missing that patch too.
>>>
>>> Here's the change for palmas:
>>>
>>> From: Felipe Balbi <balbi@ti.com>
>>> Subject: extcon: palmas: fix regression on extcon-next
>>>
>>> All extcon users must rely on devm_extcon_dev_allocate() otherwise
>>> device registration will fail.
>>>
>>> Signed-of-by: Felipe Balbi <balbi@ti.com>
>>
>> I sent already following patch to use devm_extcon_dev_* function 
>> But, following patch didn't get ack or review message from mfd maintainer and author.
>> So, I have not yet to merge this patch on extcon-next branch
>> [1]
>> [PATCHv2 6/9] extcon: palmas: Use devm_extcon_dev_allocate for extcon_dev
>> - https://lkml.org/lkml/2014/4/21/162
>>
>> If you possible, I'd like you to test this patch[1] based on extcon-next branch.
> 
> I'll do that. I can't seem to find that patch in my inbox even though
> I'm in Cc.
> 
> One thing though, the current order of your next branch will create a
> non-bisectable history, you need to shuffle things around to avoid this
> not working spots.
> 

I'm sorry about this mistake.

As you comment, I would have modified both extcon core and extcon provider driver on following patch[1]. 
[1]
[PATCHv2 1/9] extcon: Add extcon_dev_allocate/free() to control the memory of extcon device
- https://lkml.org/lkml/2014/4/21/164

I'll solve bisectable history by sending new patchset(v3).

Thanks for your comment.
Chanwoo Choi


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Felipe Balbi April 24, 2014, 2:13 p.m. UTC | #4
On Thu, Apr 24, 2014 at 05:13:09PM +0900, Chanwoo Choi wrote:
> Hi,
> 
> On 04/24/2014 03:47 PM, Felipe Balbi wrote:
> > Hi,
> > 
> > On Thu, Apr 24, 2014 at 02:35:44PM +0900, Chanwoo Choi wrote:
> >> Hi Felipe,
> >>
> >> Thanks for your test and review.
> >>
> >> On 04/24/2014 03:28 AM, Felipe Balbi wrote:
> >>> Hi,
> >>>
> >>> On Wed, Apr 23, 2014 at 12:20:52PM -0500, Felipe Balbi wrote:
> >>>>> I've been testing extcon-next to make sure USB3 on OMAP5 will work out
> >>>>> of the box but I see a regression when I merge your tree on top of
> >>>>> v3.15-rc2 + Tony's DT fixes.
> >>>>>
> >>>>> Here's what I see (trimmed):
> >>>>>
> >>>>> [    1.805870] palmas 0-0048: Muxing GPIO 2, PWM 0, LED 0
> >>>>> [    1.812516] ------------[ cut here ]------------
> >>>>> [    1.817387] WARNING: CPU: 0 PID: 6 at include/linux/kref.h:47 kobject_get+0x64/0x78()
> >>>>> [    1.817691]  mmcblk0boot1: unknown partition table
> >>>>> [    1.830601] Modules linked in:
> >>>>> [    1.833827] CPU: 0 PID: 6 Comm: kworker/u4:0 Tainted: G        W     3.15.0-rc2-00041-g3019b77 #308
> >>>>> [    1.843333] Workqueue: deferwq deferred_probe_work_func
> >>>>> [    1.848728]  mmcblk0boot0: unknown partition table
> >>>>> [    1.853928] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
> >>>>> [    1.862086] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
> >>>>> [    1.869667] [<c05426b4>] (dump_stack) from [<c0040928>] (warn_slowpath_common+0x6c/0x90)
> >>>>> [    1.878181] [<c0040928>] (warn_slowpath_common) from [<c00409e8>] (warn_slowpath_null+0x1c/0x24)
> >>>>> [    1.887421] [<c00409e8>] (warn_slowpath_null) from [<c02d50c4>] (kobject_get+0x64/0x78)
> >>>>> [    1.895837] [<c02d50c4>] (kobject_get) from [<c0350188>] (device_add+0x18/0x520)
> >>>>> [    1.903629] [<c0350188>] (device_add) from [<c0462a5c>] (extcon_dev_register+0x48/0x104)
> >>>>> [    1.912145] [<c0462a5c>] (extcon_dev_register) from [<c0462b44>] (devm_extcon_dev_register+0x2c/0x68)
> >>>>> [    1.921847] [<c0462b44>] (devm_extcon_dev_register) from [<c04630c0>] (palmas_usb_probe+0x110/0x304)
> >>>>> [    1.931453] [<c04630c0>] (palmas_usb_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> >>>>> [    1.940333] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>>>> [    1.949664] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>>>> [    1.958634] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>>>> [    1.967003] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>>>> [    1.975387] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> >>>>> [    1.983678] [<c0350590>] (device_add) from [<c045a310>] (of_platform_device_create_pdata+0x6c/0x8c)
> >>>>> [    1.993155] [<c045a310>] (of_platform_device_create_pdata) from [<c045a418>] (of_platform_bus_create+0xdc/0x168)
> >>>>> [    2.003818] [<c045a418>] (of_platform_bus_create) from [<c045a5cc>] (of_platform_populate+0x5c/0xa0)
> >>>>> [    2.013399] [<c045a5cc>] (of_platform_populate) from [<c0373c78>] (palmas_i2c_probe+0x30c/0x584)
> >>>>> [    2.022606] [<c0373c78>] (palmas_i2c_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>>>> [    2.031722] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>>>> [    2.040715] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>>>> [    2.049098] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>>>> [    2.057482] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> >>>>> [    2.065774] [<c0350590>] (device_add) from [<c0424020>] (i2c_new_device+0x12c/0x18c)
> >>>>> [    2.073885] [<c0424020>] (i2c_new_device) from [<c0424980>] (i2c_register_adapter+0x278/0x498)
> >>>>> [    2.082903] [<c0424980>] (i2c_register_adapter) from [<c04275c0>] (omap_i2c_probe+0x4a4/0x6d0)
> >>>>> [    2.091925] [<c04275c0>] (omap_i2c_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> >>>>> [    2.100582] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>>>> [    2.109883] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>>>> [    2.118823] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>>>> [    2.127194] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>>>> [    2.135584] [<c035206c>] (bus_probe_device) from [<c03524ac>] (deferred_probe_work_func+0x64/0x94)
> >>>>> [    2.144975] [<c03524ac>] (deferred_probe_work_func) from [<c0058c70>] (process_one_work+0x1ac/0x4cc)
> >>>>> [    2.154545] [<c0058c70>] (process_one_work) from [<c0059b10>] (worker_thread+0x114/0x3b4)
> >>>>> [    2.163119] [<c0059b10>] (worker_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
> >>>>> [    2.170695] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
> >>>>> [    2.178259] ---[ end trace 3006de6450234d28 ]---
> >>>>> [    2.183081] kobject 'palmas_usb' (eca58c38): tried to add an uninitialized object, something is seriously wrong.
> >>>>> [    2.193731] CPU: 0 PID: 6 Comm: kworker/u4:0 Tainted: G        W     3.15.0-rc2-00041-g3019b77 #308
> >>>>> [    2.203201] Workqueue: deferwq deferred_probe_work_func
> >>>>> [    2.208687] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
> >>>>> [    2.216789] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
> >>>>> [    2.224357] [<c05426b4>] (dump_stack) from [<c02d5c28>] (kobject_add+0x88/0x98)
> >>>>> [    2.232014] [<c02d5c28>] (kobject_add) from [<c0350250>] (device_add+0xe0/0x520)
> >>>>> [    2.239758] [<c0350250>] (device_add) from [<c0462a5c>] (extcon_dev_register+0x48/0x104)
> >>>>> [    2.248235] [<c0462a5c>] (extcon_dev_register) from [<c0462b44>] (devm_extcon_dev_register+0x2c/0x68)
> >>>>> [    2.257901] [<c0462b44>] (devm_extcon_dev_register) from [<c04630c0>] (palmas_usb_probe+0x110/0x304)
> >>>>> [    2.267467] [<c04630c0>] (palmas_usb_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> >>>>> [    2.276298] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>>>> [    2.285591] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>>>> [    2.294520] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>>>> [    2.302905] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>>>> [    2.311286] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> >>>>> [    2.319583] [<c0350590>] (device_add) from [<c045a310>] (of_platform_device_create_pdata+0x6c/0x8c)
> >>>>> [    2.329063] [<c045a310>] (of_platform_device_create_pdata) from [<c045a418>] (of_platform_bus_create+0xdc/0x168)
> >>>>> [    2.339725] [<c045a418>] (of_platform_bus_create) from [<c045a5cc>] (of_platform_populate+0x5c/0xa0)
> >>>>> [    2.349296] [<c045a5cc>] (of_platform_populate) from [<c0373c78>] (palmas_i2c_probe+0x30c/0x584)
> >>>>> [    2.358496] [<c0373c78>] (palmas_i2c_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>>>> [    2.367609] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>>>> [    2.376523] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>>>> [    2.384914] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>>>> [    2.393301] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> >>>>> [    2.401601] [<c0350590>] (device_add) from [<c0424020>] (i2c_new_device+0x12c/0x18c)
> >>>>> [    2.409707] [<c0424020>] (i2c_new_device) from [<c0424980>] (i2c_register_adapter+0x278/0x498)
> >>>>> [    2.418727] [<c0424980>] (i2c_register_adapter) from [<c04275c0>] (omap_i2c_probe+0x4a4/0x6d0)
> >>>>> [    2.427741] [<c04275c0>] (omap_i2c_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> >>>>> [    2.436382] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>>>> [    2.445680] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>>>> [    2.454613] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>>>> [    2.463001] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>>>> [    2.471385] [<c035206c>] (bus_probe_device) from [<c03524ac>] (deferred_probe_work_func+0x64/0x94)
> >>>>> [    2.480772] [<c03524ac>] (deferred_probe_work_func) from [<c0058c70>] (process_one_work+0x1ac/0x4cc)
> >>>>> [    2.490339] [<c0058c70>] (process_one_work) from [<c0059b10>] (worker_thread+0x114/0x3b4)
> >>>>> [    2.498906] [<c0059b10>] (worker_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
> >>>>> [    2.506460] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
> >>>>> [    2.514023] ------------[ cut here ]------------
> >>>>> [    2.518870] WARNING: CPU: 0 PID: 6 at lib/kobject.c:670 kobject_put+0x80/0x90()
> >>>>> [    2.526514] kobject: 'palmas_usb' (eca58c38): is not initialized, yet kobject_put() is being called.
> >>>>> [    2.536076] Modules linked in:
> >>>>> [    2.539287] CPU: 0 PID: 6 Comm: kworker/u4:0 Tainted: G        W     3.15.0-rc2-00041-g3019b77 #308
> >>>>> [    2.548753] Workqueue: deferwq deferred_probe_work_func
> >>>>> [    2.554223] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
> >>>>> [    2.562341] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
> >>>>> [    2.569911] [<c05426b4>] (dump_stack) from [<c0040928>] (warn_slowpath_common+0x6c/0x90)
> >>>>> [    2.578391] [<c0040928>] (warn_slowpath_common) from [<c004097c>] (warn_slowpath_fmt+0x30/0x40)
> >>>>> [    2.587502] [<c004097c>] (warn_slowpath_fmt) from [<c02d5158>] (kobject_put+0x80/0x90)
> >>>>> [    2.595780] [<c02d5158>] (kobject_put) from [<c03502fc>] (device_add+0x18c/0x520)
> >>>>> [    2.603623] [<c03502fc>] (device_add) from [<c0462a5c>] (extcon_dev_register+0x48/0x104)
> >>>>> [    2.612103] [<c0462a5c>] (extcon_dev_register) from [<c0462b44>] (devm_extcon_dev_register+0x2c/0x68)
> >>>>> [    2.621762] [<c0462b44>] (devm_extcon_dev_register) from [<c04630c0>] (palmas_usb_probe+0x110/0x304)
> >>>>> [    2.631321] [<c04630c0>] (palmas_usb_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> >>>>> [    2.640161] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>>>> [    2.649447] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>>>> [    2.658386] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>>>> [    2.666757] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>>>> [    2.675144] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> >>>>> [    2.683441] [<c0350590>] (device_add) from [<c045a310>] (of_platform_device_create_pdata+0x6c/0x8c)
> >>>>> [    2.692921] [<c045a310>] (of_platform_device_create_pdata) from [<c045a418>] (of_platform_bus_create+0xdc/0x168)
> >>>>> [    2.703575] [<c045a418>] (of_platform_bus_create) from [<c045a5cc>] (of_platform_populate+0x5c/0xa0)
> >>>>> [    2.713139] [<c045a5cc>] (of_platform_populate) from [<c0373c78>] (palmas_i2c_probe+0x30c/0x584)
> >>>>> [    2.722341] [<c0373c78>] (palmas_i2c_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>>>> [    2.731457] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>>>> [    2.740380] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>>>> [    2.748764] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>>>> [    2.757135] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> >>>>> [    2.765429] [<c0350590>] (device_add) from [<c0424020>] (i2c_new_device+0x12c/0x18c)
> >>>>> [    2.773549] [<c0424020>] (i2c_new_device) from [<c0424980>] (i2c_register_adapter+0x278/0x498)
> >>>>> [    2.782576] [<c0424980>] (i2c_register_adapter) from [<c04275c0>] (omap_i2c_probe+0x4a4/0x6d0)
> >>>>> [    2.791597] [<c04275c0>] (omap_i2c_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> >>>>> [    2.800261] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>>>> [    2.809560] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>>>> [    2.818489] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>>>> [    2.826865] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>>>> [    2.835253] [<c035206c>] (bus_probe_device) from [<c03524ac>] (deferred_probe_work_func+0x64/0x94)
> >>>>> [    2.844637] [<c03524ac>] (deferred_probe_work_func) from [<c0058c70>] (process_one_work+0x1ac/0x4cc)
> >>>>> [    2.854205] [<c0058c70>] (process_one_work) from [<c0059b10>] (worker_thread+0x114/0x3b4)
> >>>>> [    2.862778] [<c0059b10>] (worker_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
> >>>>> [    2.870349] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
> >>>>> [    2.877911] ---[ end trace 3006de6450234d29 ]---
> >>>>> [    2.882734] ------------[ cut here ]------------
> >>>>> [    2.887573] WARNING: CPU: 0 PID: 6 at lib/kobject.c:670 kobject_put+0x80/0x90()
> >>>>> [    2.895209] kobject: 'palmas_usb' (eca58c38): is not initialized, yet kobject_put() is being called.
> >>>>> [    2.904765] Modules linked in:
> >>>>> [    2.907971] CPU: 0 PID: 6 Comm: kworker/u4:0 Tainted: G        W     3.15.0-rc2-00041-g3019b77 #308
> >>>>> [    2.917447] Workqueue: deferwq deferred_probe_work_func
> >>>>> [    2.922924] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
> >>>>> [    2.931033] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
> >>>>> [    2.938606] [<c05426b4>] (dump_stack) from [<c0040928>] (warn_slowpath_common+0x6c/0x90)
> >>>>> [    2.947069] [<c0040928>] (warn_slowpath_common) from [<c004097c>] (warn_slowpath_fmt+0x30/0x40)
> >>>>> [    2.956187] [<c004097c>] (warn_slowpath_fmt) from [<c02d5158>] (kobject_put+0x80/0x90)
> >>>>> [    2.964483] [<c02d5158>] (kobject_put) from [<c0462abc>] (extcon_dev_register+0xa8/0x104)
> >>>>> [    2.973053] [<c0462abc>] (extcon_dev_register) from [<c0462b44>] (devm_extcon_dev_register+0x2c/0x68)
> >>>>> [    2.982718] [<c0462b44>] (devm_extcon_dev_register) from [<c04630c0>] (palmas_usb_probe+0x110/0x304)
> >>>>> [    2.992285] [<c04630c0>] (palmas_usb_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> >>>>> [    3.001124] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>>>> [    3.010423] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>>>> [    3.019358] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>>>> [    3.027746] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>>>> [    3.036121] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> >>>>> [    3.044418] [<c0350590>] (device_add) from [<c045a310>] (of_platform_device_create_pdata+0x6c/0x8c)
> >>>>> [    3.053893] [<c045a310>] (of_platform_device_create_pdata) from [<c045a418>] (of_platform_bus_create+0xdc/0x168)
> >>>>> [    3.064550] [<c045a418>] (of_platform_bus_create) from [<c045a5cc>] (of_platform_populate+0x5c/0xa0)
> >>>>> [    3.074124] [<c045a5cc>] (of_platform_populate) from [<c0373c78>] (palmas_i2c_probe+0x30c/0x584)
> >>>>> [    3.083338] [<c0373c78>] (palmas_i2c_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>>>> [    3.092447] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>>>> [    3.101381] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>>>> [    3.109767] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>>>> [    3.118147] [<c035206c>] (bus_probe_device) from [<c0350590>] (device_add+0x420/0x520)
> >>>>> [    3.126432] [<c0350590>] (device_add) from [<c0424020>] (i2c_new_device+0x12c/0x18c)
> >>>>> [    3.134547] [<c0424020>] (i2c_new_device) from [<c0424980>] (i2c_register_adapter+0x278/0x498)
> >>>>> [    3.143569] [<c0424980>] (i2c_register_adapter) from [<c04275c0>] (omap_i2c_probe+0x4a4/0x6d0)
> >>>>> [    3.152593] [<c04275c0>] (omap_i2c_probe) from [<c0354284>] (platform_drv_probe+0x18/0x48)
> >>>>> [    3.161249] [<c0354284>] (platform_drv_probe) from [<c0352b0c>] (driver_probe_device+0x110/0x22c)
> >>>>> [    3.170537] [<c0352b0c>] (driver_probe_device) from [<c03511a0>] (bus_for_each_drv+0x58/0x8c)
> >>>>> [    3.179472] [<c03511a0>] (bus_for_each_drv) from [<c03529c8>] (device_attach+0x74/0x8c)
> >>>>> [    3.187854] [<c03529c8>] (device_attach) from [<c035206c>] (bus_probe_device+0x88/0xb0)
> >>>>> [    3.196222] [<c035206c>] (bus_probe_device) from [<c03524ac>] (deferred_probe_work_func+0x64/0x94)
> >>>>> [    3.205611] [<c03524ac>] (deferred_probe_work_func) from [<c0058c70>] (process_one_work+0x1ac/0x4cc)
> >>>>> [    3.215174] [<c0058c70>] (process_one_work) from [<c0059b10>] (worker_thread+0x114/0x3b4)
> >>>>> [    3.223739] [<c0059b10>] (worker_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
> >>>>> [    3.231313] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
> >>>>> [    3.238883] ---[ end trace 3006de6450234d2a ]---
> >>>>> [    3.243711] palmas-usb palmas_usb.7: failed to register extcon device
> >>>>> [    3.250493] palmas-usb: probe of palmas_usb.7 failed with error -22
> >>>>>
> >>>>> Any ideas ??
> >>>>
> >>>> bisected down to:
> >>>>
> >>>> commit 854b85057cc6b90a326b731174b6c6dbbf34222a
> >>>> Author: Chanwoo Choi <cw00.choi@samsung.com>
> >>>> Date:   Mon Apr 21 19:46:51 2014 +0900
> >>>>
> >>>>     extcon: Add extcon_dev_allocate/free() to control the memory of extcon device
> >>>>     
> >>>>     This patch add APIs to control the extcon device on extcon provider driver.
> >>>>     The extcon_dev_allocate() allocates the memory of extcon device and initializes
> >>>>     supported cables. And then extcon_dev_free() decrement the reference of the
> >>>>     device of extcon device and free the memory of the extcon device. This APIs
> >>>>     must need to implement devm_extcon_dev_allocate()/free() APIs.
> >>>>     
> >>>>     Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
> >>>>
> >>>> diff --git a/drivers/extcon/extcon-class.c b/drivers/extcon/extcon-class.c
> >>>> index f6df689..3e485bc 100644
> >>>> --- a/drivers/extcon/extcon-class.c
> >>>> +++ b/drivers/extcon/extcon-class.c
> >>>> @@ -558,6 +558,9 @@ static int create_extcon_class(void)
> >>>>  
> >>>>  static void extcon_dev_release(struct device *dev)
> >>>>  {
> >>>> +	struct extcon_dev *edev = dev_to_extcon_dev(dev);
> >>>> +
> >>>> +	kfree(edev);
> >>>>  }
> >>>>  
> >>>>  static const char *muex_name = "mutually_exclusive";
> >>>> @@ -576,7 +579,7 @@ static void dummy_sysfs_dev_release(struct device *dev)
> >>>>   */
> >>>>  int extcon_dev_register(struct extcon_dev *edev)
> >>>>  {
> >>>> -	int ret, index = 0;
> >>>> +	int ret;
> >>>>  
> >>>>  	if (!extcon_class) {
> >>>>  		ret = create_extcon_class();
> >>>> @@ -584,80 +587,150 @@ int extcon_dev_register(struct extcon_dev *edev)
> >>>>  			return ret;
> >>>>  	}
> >>>>  
> >>>> -	if (edev->supported_cable) {
> >>>> -		/* Get size of array */
> >>>> -		for (index = 0; edev->supported_cable[index]; index++)
> >>>> -			;
> >>>> -		edev->max_supported = index;
> >>>> -	} else {
> >>>> -		edev->max_supported = 0;
> >>>> +	edev->name = edev->name ? edev->name : dev_name(edev->dev.parent);
> >>>> +	if (IS_ERR_OR_NULL(edev->name)) {
> >>>> +		dev_err(&edev->dev, "extcon device name is null\n");
> >>>> +		return -EINVAL;
> >>>>  	}
> >>>> +	dev_set_name(&edev->dev, "%s", edev->name);
> >>>>  
> >>>> -	if (index > SUPPORTED_CABLE_MAX) {
> >>>> -		dev_err(&edev->dev, "extcon: maximum number of supported cables exceeded.\n");
> >>>> -		return -EINVAL;
> >>>> +	ret = device_add(&edev->dev);
> >>>> +	if (ret) {
> >>>> +		put_device(&edev->dev);
> >>>> +		return ret;
> >>>>  	}
> >>>> +#if defined(CONFIG_ANDROID)
> >>>> +	if (switch_class)
> >>>> +		ret = class_compat_create_link(switch_class, &edev->dev, NULL);
> >>>> +#endif /* CONFIG_ANDROID */
> >>>>  
> >>>> -	edev->dev.class = extcon_class;
> >>>> -	edev->dev.release = extcon_dev_release;
> >>>> +	RAW_INIT_NOTIFIER_HEAD(&edev->nh);
> >>>>  
> >>>> -	edev->name = edev->name ? edev->name : dev_name(edev->dev.parent);
> >>>> -	if (IS_ERR_OR_NULL(edev->name)) {
> >>>> -		dev_err(&edev->dev,
> >>>> -			"extcon device name is null\n");
> >>>> -		return -EINVAL;
> >>>> +	dev_set_drvdata(&edev->dev, edev);
> >>>> +	edev->state = 0;
> >>>> +
> >>>> +	mutex_lock(&extcon_dev_list_lock);
> >>>> +	list_add(&edev->entry, &extcon_dev_list);
> >>>> +	mutex_unlock(&extcon_dev_list_lock);
> >>>> +
> >>>> +	return 0;
> >>>> +}
> >>>> +EXPORT_SYMBOL_GPL(extcon_dev_register);
> >>>> +
> >>>> +/**
> >>>> + * extcon_dev_unregister() - Unregister the extcon device.
> >>>> + * @edev:	the extcon device instance to be unregistered.
> >>>> + */
> >>>> +void extcon_dev_unregister(struct extcon_dev *edev)
> >>>> +{
> >>>> +	mutex_lock(&extcon_dev_list_lock);
> >>>> +	list_del(&edev->entry);
> >>>> +	mutex_unlock(&extcon_dev_list_lock);
> >>>> +
> >>>> +	if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
> >>>> +		dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
> >>>> +				dev_name(&edev->dev));
> >>>> +		return;
> >>>>  	}
> >>>> -	dev_set_name(&edev->dev, "%s", edev->name);
> >>>>  
> >>>> -	if (edev->max_supported) {
> >>>> -		char buf[10];
> >>>> -		char *str;
> >>>> -		struct extcon_cable *cable;
> >>>> +	device_unregister(&edev->dev);
> >>>>  
> >>>> -		edev->cables = kzalloc(sizeof(struct extcon_cable) *
> >>>> -				       edev->max_supported, GFP_KERNEL);
> >>>> -		if (!edev->cables) {
> >>>> +#if defined(CONFIG_ANDROID)
> >>>> +	if (switch_class)
> >>>> +		class_compat_remove_link(switch_class, &edev->dev, NULL);
> >>>> +#endif
> >>>> +}
> >>>> +EXPORT_SYMBOL_GPL(extcon_dev_unregister);
> >>>> +
> >>>> +/*
> >>>> + * extcon_dev_allocate() - Allocate the memory of extcon device.
> >>>> + * @supported_cable:	Array of supported cable names ending with NULL.
> >>>> + *			If supported_cable is NULL, cable name related APIs
> >>>> + *			are disabled.
> >>>> + *
> >>>> + * This function allocates the memory for extcon device without allocating
> >>>> + * memory in each extcon provider driver and initialize default setting for
> >>>> + * extcon device.
> >>>> + *
> >>>> + * Return the pointer of extcon device if success or ERR_PTR(err) if fail
> >>>> + */
> >>>> +struct extcon_dev *extcon_dev_allocate(const char **supported_cable)
> >>>> +{
> >>>> +	struct extcon_dev *edev;
> >>>> +	int index, ret, count = 0;
> >>>> +
> >>>> +	edev = kzalloc(sizeof(*edev), GFP_KERNEL);
> >>>> +	if (!edev) {
> >>>> +		pr_err("Failed to allocate the memory for extcon device\n");
> >>>> +		return ERR_PTR(-ENOMEM);
> >>>> +	}
> >>>> +
> >>>> +	edev->max_supported = 0;
> >>>> +	edev->supported_cable = supported_cable;
> >>>> +	if (edev->supported_cable) {
> >>>> +		for (count = 0; edev->supported_cable[count]; count++)
> >>>> +			;
> >>>> +		edev->max_supported = count;
> >>>> +		if (count > SUPPORTED_CABLE_MAX) {
> >>>> +			pr_err("Exceed max number of supported cables\n");
> >>>>  			ret = -ENOMEM;
> >>>> -			goto err_sysfs_alloc;
> >>>> +			goto err;
> >>>>  		}
> >>>> -		for (index = 0; index < edev->max_supported; index++) {
> >>>> -			cable = &edev->cables[index];
> >>>> +	}
> >>>>  
> >>>> -			snprintf(buf, 10, "cable.%d", index);
> >>>> -			str = kzalloc(sizeof(char) * (strlen(buf) + 1),
> >>>> -				      GFP_KERNEL);
> >>>> -			if (!str) {
> >>>> -				for (index--; index >= 0; index--) {
> >>>> -					cable = &edev->cables[index];
> >>>> -					kfree(cable->attr_g.name);
> >>>> -				}
> >>>> -				ret = -ENOMEM;
> >>>> +	edev->dev.class = extcon_class;
> >>>> +	edev->dev.release = extcon_dev_release;
> >>>> +	device_initialize(&edev->dev);
> >>>> +	spin_lock_init(&edev->lock);
> >>>> +
> >>>> +	if (!edev->max_supported)
> >>>> +		return 0;
> >>>> +
> >>>> +	edev->cables = kzalloc(sizeof(struct extcon_cable) *
> >>>> +			       edev->max_supported, GFP_KERNEL);
> >>>> +	if (!edev->cables) {
> >>>> +		ret = -ENOMEM;
> >>>> +		goto err;
> >>>> +	}
> >>>>  
> >>>> -				goto err_alloc_cables;
> >>>> +	for (index = 0; index < edev->max_supported; index++) {
> >>>> +		struct extcon_cable *cable = &edev->cables[index];
> >>>> +		char buf[10];
> >>>> +		char *str;
> >>>> +
> >>>> +		snprintf(buf, 10, "cable.%d", index);
> >>>> +		str = kzalloc(sizeof(char) * (strlen(buf) + 1),
> >>>> +			      GFP_KERNEL);
> >>>> +		if (!str) {
> >>>> +			for (index--; index >= 0; index--) {
> >>>> +				cable = &edev->cables[index];
> >>>> +				kfree(cable->attr_g.name);
> >>>>  			}
> >>>> -			strcpy(str, buf);
> >>>> -
> >>>> -			cable->edev = edev;
> >>>> -			cable->cable_index = index;
> >>>> -			cable->attrs[0] = &cable->attr_name.attr;
> >>>> -			cable->attrs[1] = &cable->attr_state.attr;
> >>>> -			cable->attrs[2] = NULL;
> >>>> -			cable->attr_g.name = str;
> >>>> -			cable->attr_g.attrs = cable->attrs;
> >>>> -
> >>>> -			sysfs_attr_init(&cable->attr_name.attr);
> >>>> -			cable->attr_name.attr.name = "name";
> >>>> -			cable->attr_name.attr.mode = 0444;
> >>>> -			cable->attr_name.show = cable_name_show;
> >>>> -
> >>>> -			sysfs_attr_init(&cable->attr_state.attr);
> >>>> -			cable->attr_state.attr.name = "state";
> >>>> -			cable->attr_state.attr.mode = 0444;
> >>>> -			cable->attr_state.show = cable_state_show;
> >>>> +			ret = -ENOMEM;
> >>>> +			goto err_alloc_cables;
> >>>>  		}
> >>>> +		strcpy(str, buf);
> >>>> +
> >>>> +		cable->edev = edev;
> >>>> +		cable->cable_index = index;
> >>>> +		cable->attrs[0] = &cable->attr_name.attr;
> >>>> +		cable->attrs[1] = &cable->attr_state.attr;
> >>>> +		cable->attrs[2] = NULL;
> >>>> +		cable->attr_g.name = str;
> >>>> +		cable->attr_g.attrs = cable->attrs;
> >>>> +
> >>>> +		sysfs_attr_init(&cable->attr_name.attr);
> >>>> +		cable->attr_name.attr.name = "name";
> >>>> +		cable->attr_name.attr.mode = 0444;
> >>>> +		cable->attr_name.show = cable_name_show;
> >>>> +
> >>>> +		sysfs_attr_init(&cable->attr_state.attr);
> >>>> +		cable->attr_state.attr.name = "state";
> >>>> +		cable->attr_state.attr.mode = 0444;
> >>>> +		cable->attr_state.show = cable_state_show;
> >>>>  	}
> >>>>  
> >>>> -	if (edev->max_supported && edev->mutually_exclusive) {
> >>>> +	if (edev->mutually_exclusive) {
> >>>>  		char buf[80];
> >>>>  		char *name;
> >>>>  
> >>>> @@ -703,59 +776,32 @@ int extcon_dev_register(struct extcon_dev *edev)
> >>>>  		}
> >>>>  		edev->attr_g_muex.name = muex_name;
> >>>>  		edev->attr_g_muex.attrs = edev->attrs_muex;
> >>>> -
> >>>>  	}
> >>>>  
> >>>> -	if (edev->max_supported) {
> >>>> -		edev->extcon_dev_type.groups =
> >>>> -			kzalloc(sizeof(struct attribute_group *) *
> >>>> -				(edev->max_supported + 2), GFP_KERNEL);
> >>>> -		if (!edev->extcon_dev_type.groups) {
> >>>> -			ret = -ENOMEM;
> >>>> -			goto err_alloc_groups;
> >>>> -		}
> >>>> -
> >>>> -		edev->extcon_dev_type.name = dev_name(&edev->dev);
> >>>> -		edev->extcon_dev_type.release = dummy_sysfs_dev_release;
> >>>> -
> >>>> -		for (index = 0; index < edev->max_supported; index++)
> >>>> -			edev->extcon_dev_type.groups[index] =
> >>>> -				&edev->cables[index].attr_g;
> >>>> -		if (edev->mutually_exclusive)
> >>>> -			edev->extcon_dev_type.groups[index] =
> >>>> -				&edev->attr_g_muex;
> >>>> -
> >>>> -		edev->dev.type = &edev->extcon_dev_type;
> >>>> +	edev->extcon_dev_type.groups =
> >>>> +		kzalloc(sizeof(struct attribute_group *) *
> >>>> +			(edev->max_supported + 2), GFP_KERNEL);
> >>>> +	if (!edev->extcon_dev_type.groups) {
> >>>> +		ret = -ENOMEM;
> >>>> +		goto err_alloc_groups;
> >>>>  	}
> >>>>  
> >>>> -	ret = device_register(&edev->dev);
> >>>> -	if (ret) {
> >>>> -		put_device(&edev->dev);
> >>>> -		goto err_dev;
> >>>> -	}
> >>>> -#if defined(CONFIG_ANDROID)
> >>>> -	if (switch_class)
> >>>> -		ret = class_compat_create_link(switch_class, &edev->dev, NULL);
> >>>> -#endif /* CONFIG_ANDROID */
> >>>> -
> >>>> -	spin_lock_init(&edev->lock);
> >>>> -
> >>>> -	RAW_INIT_NOTIFIER_HEAD(&edev->nh);
> >>>> +	edev->extcon_dev_type.name = dev_name(&edev->dev);
> >>>> +	edev->extcon_dev_type.release = dummy_sysfs_dev_release;
> >>>>  
> >>>> -	dev_set_drvdata(&edev->dev, edev);
> >>>> -	edev->state = 0;
> >>>> +	for (index = 0; index < edev->max_supported; index++)
> >>>> +		edev->extcon_dev_type.groups[index] =
> >>>> +			&edev->cables[index].attr_g;
> >>>> +	if (edev->mutually_exclusive)
> >>>> +		edev->extcon_dev_type.groups[index] =
> >>>> +			&edev->attr_g_muex;
> >>>>  
> >>>> -	mutex_lock(&extcon_dev_list_lock);
> >>>> -	list_add(&edev->entry, &extcon_dev_list);
> >>>> -	mutex_unlock(&extcon_dev_list_lock);
> >>>> +	edev->dev.type = &edev->extcon_dev_type;
> >>>>  
> >>>> -	return 0;
> >>>> +	return edev;
> >>>>  
> >>>> -err_dev:
> >>>> -	if (edev->max_supported)
> >>>> -		kfree(edev->extcon_dev_type.groups);
> >>>>  err_alloc_groups:
> >>>> -	if (edev->max_supported && edev->mutually_exclusive) {
> >>>> +	if (edev->mutually_exclusive) {
> >>>>  		for (index = 0; edev->mutually_exclusive[index]; index++)
> >>>>  			kfree(edev->d_attrs_muex[index].attr.name);
> >>>>  		kfree(edev->d_attrs_muex);
> >>>> @@ -765,36 +811,22 @@ err_muex:
> >>>>  	for (index = 0; index < edev->max_supported; index++)
> >>>>  		kfree(edev->cables[index].attr_g.name);
> >>>>  err_alloc_cables:
> >>>> -	if (edev->max_supported)
> >>>> -		kfree(edev->cables);
> >>>> -err_sysfs_alloc:
> >>>> -	return ret;
> >>>> +	kfree(edev->cables);
> >>>> +err:
> >>>> +	kfree(edev);
> >>>> +
> >>>> +	return ERR_PTR(ret);
> >>>>  }
> >>>> -EXPORT_SYMBOL_GPL(extcon_dev_register);
> >>>> +EXPORT_SYMBOL_GPL(extcon_dev_allocate);
> >>>>  
> >>>> -/**
> >>>> - * extcon_dev_unregister() - Unregister the extcon device.
> >>>> - * @edev:	the extcon device instance to be unregistered.
> >>>> - *
> >>>> - * Note that this does not call kfree(edev) because edev was not allocated
> >>>> - * by this class.
> >>>> +/*
> >>>> + * extcon_dev_free() - Free the memory of extcon device.
> >>>> + * @edev:	the extcon device to free
> >>>>   */
> >>>> -void extcon_dev_unregister(struct extcon_dev *edev)
> >>>> +void extcon_dev_free(struct extcon_dev *edev)
> >>>>  {
> >>>>  	int index;
> >>>>  
> >>>> -	mutex_lock(&extcon_dev_list_lock);
> >>>> -	list_del(&edev->entry);
> >>>> -	mutex_unlock(&extcon_dev_list_lock);
> >>>> -
> >>>> -	if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
> >>>> -		dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
> >>>> -				dev_name(&edev->dev));
> >>>> -		return;
> >>>> -	}
> >>>> -
> >>>> -	device_unregister(&edev->dev);
> >>>> -
> >>>>  	if (edev->mutually_exclusive && edev->max_supported) {
> >>>>  		for (index = 0; edev->mutually_exclusive[index];
> >>>>  				index++)
> >>>> @@ -811,13 +843,10 @@ void extcon_dev_unregister(struct extcon_dev *edev)
> >>>>  		kfree(edev->cables);
> >>>>  	}
> >>>>  
> >>>> -#if defined(CONFIG_ANDROID)
> >>>> -	if (switch_class)
> >>>> -		class_compat_remove_link(switch_class, &edev->dev, NULL);
> >>>> -#endif
> >>>> -	put_device(&edev->dev);
> >>>> +	if (edev)
> >>>> +		put_device(&edev->dev);
> >>>>  }
> >>>> -EXPORT_SYMBOL_GPL(extcon_dev_unregister);
> >>>> +EXPORT_SYMBOL_GPL(extcon_dev_free);
> >>>>  
> >>>>  static void devm_extcon_dev_unreg(struct device *dev, void *res)
> >>>>  {
> >>>> diff --git a/include/linux/extcon.h b/include/linux/extcon.h
> >>>> index 85a8a5b..20587ee 100644
> >>>> --- a/include/linux/extcon.h
> >>>> +++ b/include/linux/extcon.h
> >>>> @@ -179,6 +179,8 @@ struct extcon_specific_cable_nb {
> >>>>  
> >>>>  #if IS_ENABLED(CONFIG_EXTCON)
> >>>>  
> >>>> +#define dev_to_extcon_dev(d) container_of(d, struct extcon_dev, dev)
> >>>> +
> >>>>  /*
> >>>>   * Following APIs are for notifiers or configurations.
> >>>>   * Notifiers are the external port and connection devices.
> >>>> @@ -250,6 +252,12 @@ extern int extcon_unregister_notifier(struct extcon_dev *edev,
> >>>>  				      struct notifier_block *nb);
> >>>>  
> >>>>  /*
> >>>> + * Following APIs control the memory of extcon device.
> >>>> + */
> >>>> +extern struct extcon_dev *extcon_dev_allocate(const char **cables);
> >>>> +extern void extcon_dev_free(struct extcon_dev *edev);
> >>>> +
> >>>> +/*
> >>>>   * Following API get the extcon device from devicetree.
> >>>>   * This function use phandle of devicetree to get extcon device directly.
> >>>>   */
> >>>> @@ -353,5 +361,12 @@ static inline struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev,
> >>>>  {
> >>>>  	return ERR_PTR(-ENODEV);
> >>>>  }
> >>>> +
> >>>> +static inline struct extcon_dev *extcon_dev_allocate(const char **cables)
> >>>> +{
> >>>> +	return ERR_PTR(-ENOMEM);
> >>>> +}
> >>>> +
> >>>> +static inline void extcon_dev_free(struct extcon_dev *edev) { }
> >>>>  #endif /* CONFIG_EXTCON */
> >>>>  #endif /* __LINUX_EXTCON_H__ */
> >>>>
> >>>>
> >>>> here's full bisection log:
> >>>>
> >>>> git bisect start
> >>>> # good: [a798c10faf62a505d24e5f6213fbaf904a39623f] Linux 3.15-rc2
> >>>> git bisect good a798c10faf62a505d24e5f6213fbaf904a39623f
> >>>> # bad: [3019b77470c1f10b23438917f73cad386e4f7f02] Merge branch 'extcon-next' of git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/extcon into merge
> >>>> git bisect bad 3019b77470c1f10b23438917f73cad386e4f7f02
> >>>> # bad: [f68f3aeb530b1efe3d6bf583db7a6255d15544eb] extcon: max14577: Use devm_extcon_dev_allocate for extcon_dev
> >>>> git bisect bad f68f3aeb530b1efe3d6bf583db7a6255d15544eb
> >>>> # good: [489096faca790b75653478d2f9d4774dd4f07b93] extcon: gpio: Use devm_extcon_dev_register()
> >>>> git bisect good 489096faca790b75653478d2f9d4774dd4f07b93
> >>>> # good: [5a451cded8793798e0d409e6ed6f8c53785ae929] extcon: arizona: Use devm_extcon_dev_register()
> >>>> git bisect good 5a451cded8793798e0d409e6ed6f8c53785ae929
> >>>> # bad: [cbe68e2d93df61fe40ddfea4d75f169fabadc155] extcon: Add devm_extcon_dev_allocate/free to manage the resource of extcon device
> >>>> git bisect bad cbe68e2d93df61fe40ddfea4d75f169fabadc155
> >>>> # bad: [854b85057cc6b90a326b731174b6c6dbbf34222a] extcon: Add extcon_dev_allocate/free() to control the memory of extcon device
> >>>> git bisect bad 854b85057cc6b90a326b731174b6c6dbbf34222a
> >>>> # first bad commit: [854b85057cc6b90a326b731174b6c6dbbf34222a] extcon: Add extcon_dev_allocate/free() to control the memory of extcon device
> >>>>
> >>>> And the bug is very simple and affects *all* users of extcon class,
> >>>> which tells me that this big series switching over to devm_* resources
> >>>> wasn't tested at all. Originally extcon_dev_register() was calling
> >>>> device_register(&edev->dev) which will call device_initialize(dev)
> >>>> followed by device_add(dev).
> >>>>
> >>>> After this commit, extcon_dev_register() now calls
> >>>> device_add(&edev->dev) directly but never calls device_initialize()
> >>>> anywhere. Was this *ever* tested anywhere ????? I suppose not!
> >>>>
> >>>> Please fix that up ASAP.
> >>>
> >>> After fixing (actually, hacking) the first problem:
> >>>
> >>> diff --git a/drivers/extcon/extcon-class.c b/drivers/extcon/extcon-class.c
> >>> index 677c502..d1b74e8 100644
> >>> --- a/drivers/extcon/extcon-class.c
> >>> +++ b/drivers/extcon/extcon-class.c
> >>> @@ -594,7 +594,7 @@ int extcon_dev_register(struct extcon_dev *edev)
> >>>  	}
> >>>  	dev_set_name(&edev->dev, "%s", edev->name);
> >>>  
> >>> -	ret = device_add(&edev->dev);
> >>> +	ret = device_register(&edev->dev);
> >>
> >> It is not bug.
> >>
> >> As I comment on previous reply,
> >> This patchset add 'extcon_dev_allocate()' to allocate the memory of
> >> extcon device. So, extcon_dev_allocate() calls 'device_initialize("
> >> before calling extcon_dev_register() and then extcon_dev_register()
> >> calls device_add() function as following.
> >>
> >> edev = extcon_dev_allocate()
> >> 	{
> >> 		...
> >> 		device_initialize(&edev->dev) (line.683)
> >> 	}
> >>
> >> ret = extcon_dev_register(edev)
> >> 	{
> >> 		...
> >> 		device_add(&edev->dev);
> >> 		...
> >> 	}
> >>
> >>>  	if (ret) {
> >>>  		put_device(&edev->dev);
> >>>  		return ret;
> >>>
> >>> another problem shows up when connecting the USB cable:
> >>>
> >>> [   99.386598] INFO: trying to register non-static key.
> >>> [   99.391787] the code is fine but needs lockdep annotation.
> >>> [   99.397529] turning off the locking correctness validator.
> >>> [   99.403262] CPU: 1 PID: 757 Comm: irq/39-palmas Tainted: G        W     3.15.0-rc2-00041-g3019b77-dirty #315
> >>> [   99.413552] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
> >>> [   99.421658] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
> >>> [   99.429216] [<c05426b4>] (dump_stack) from [<c0085584>] (__lock_acquire+0x17c8/0x1bc0)
> >>> [   99.437498] [<c0085584>] (__lock_acquire) from [<c008617c>] (lock_acquire+0xa4/0x100)
> >>> [   99.445692] [<c008617c>] (lock_acquire) from [<c05486e0>] (_raw_spin_lock_irqsave+0x38/0x4c)
> >>> [   99.454530] [<c05486e0>] (_raw_spin_lock_irqsave) from [<c0462610>] (extcon_update_state+0x20/0x20c)
> >>> [   99.464084] [<c0462610>] (extcon_update_state) from [<c0462f6c>] (palmas_vbus_irq_handler+0x60/0xa4)
> >>> [   99.473640] [<c0462f6c>] (palmas_vbus_irq_handler) from [<c0091ce0>] (handle_nested_irq+0xa0/0x100)
> >>> [   99.483109] [<c0091ce0>] (handle_nested_irq) from [<c0368e20>] (regmap_irq_thread+0x17c/0x300)
> >>> [   99.492120] [<c0368e20>] (regmap_irq_thread) from [<c008ff20>] (irq_thread_fn+0x1c/0x40)
> >>> [   99.500586] [<c008ff20>] (irq_thread_fn) from [<c0090238>] (irq_thread+0x12c/0x188)
> >>> [   99.508600] [<c0090238>] (irq_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
> >>> [   99.515882] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
> >>> [   99.523534] palmas-usb palmas_usb.7: USB cable is attached
> >>>
> >>> Again, another sign that this was not tested! That is caused by the same
> >>> commit. It seems like you want *all* extcon users to call
> >>> devm_extcon_dev_allocate() but you didn't fix palmas to do that, I
> >>> suspect a few other drivers are missing that patch too.
> >>>
> >>> Here's the change for palmas:
> >>>
> >>> From: Felipe Balbi <balbi@ti.com>
> >>> Subject: extcon: palmas: fix regression on extcon-next
> >>>
> >>> All extcon users must rely on devm_extcon_dev_allocate() otherwise
> >>> device registration will fail.
> >>>
> >>> Signed-of-by: Felipe Balbi <balbi@ti.com>
> >>
> >> I sent already following patch to use devm_extcon_dev_* function 
> >> But, following patch didn't get ack or review message from mfd maintainer and author.
> >> So, I have not yet to merge this patch on extcon-next branch
> >> [1]
> >> [PATCHv2 6/9] extcon: palmas: Use devm_extcon_dev_allocate for extcon_dev
> >> - https://lkml.org/lkml/2014/4/21/162
> >>
> >> If you possible, I'd like you to test this patch[1] based on extcon-next branch.
> > 
> > I'll do that. I can't seem to find that patch in my inbox even though
> > I'm in Cc.
> > 
> > One thing though, the current order of your next branch will create a
> > non-bisectable history, you need to shuffle things around to avoid this
> > not working spots.
> > 
> 
> I'm sorry about this mistake.
> 
> As you comment, I would have modified both extcon core and extcon
> provider driver on following patch[1].  [1]
> [PATCHv2 1/9] extcon: Add extcon_dev_allocate/free() to control the memory of extcon device
> - https://lkml.org/lkml/2014/4/21/164

cool, I guess you need to find a way to still keep the old version
around until all users are converted, then you can remove it on a
following patch.

> I'll solve bisectable history by sending new patchset(v3).

alright, thank you. I tested your palmas change and it's working fine.

thanks
diff mbox

Patch

diff --git a/drivers/extcon/extcon-class.c b/drivers/extcon/extcon-class.c
index 677c502..d1b74e8 100644
--- a/drivers/extcon/extcon-class.c
+++ b/drivers/extcon/extcon-class.c
@@ -594,7 +594,7 @@  int extcon_dev_register(struct extcon_dev *edev)
 	}
 	dev_set_name(&edev->dev, "%s", edev->name);
 
-	ret = device_add(&edev->dev);
+	ret = device_register(&edev->dev);
 	if (ret) {
 		put_device(&edev->dev);
 		return ret;

another problem shows up when connecting the USB cable:

[   99.386598] INFO: trying to register non-static key.
[   99.391787] the code is fine but needs lockdep annotation.
[   99.397529] turning off the locking correctness validator.
[   99.403262] CPU: 1 PID: 757 Comm: irq/39-palmas Tainted: G        W     3.15.0-rc2-00041-g3019b77-dirty #315
[   99.413552] [<c0015110>] (unwind_backtrace) from [<c0011d6c>] (show_stack+0x10/0x14)
[   99.421658] [<c0011d6c>] (show_stack) from [<c05426b4>] (dump_stack+0x84/0x9c)
[   99.429216] [<c05426b4>] (dump_stack) from [<c0085584>] (__lock_acquire+0x17c8/0x1bc0)
[   99.437498] [<c0085584>] (__lock_acquire) from [<c008617c>] (lock_acquire+0xa4/0x100)
[   99.445692] [<c008617c>] (lock_acquire) from [<c05486e0>] (_raw_spin_lock_irqsave+0x38/0x4c)
[   99.454530] [<c05486e0>] (_raw_spin_lock_irqsave) from [<c0462610>] (extcon_update_state+0x20/0x20c)
[   99.464084] [<c0462610>] (extcon_update_state) from [<c0462f6c>] (palmas_vbus_irq_handler+0x60/0xa4)
[   99.473640] [<c0462f6c>] (palmas_vbus_irq_handler) from [<c0091ce0>] (handle_nested_irq+0xa0/0x100)
[   99.483109] [<c0091ce0>] (handle_nested_irq) from [<c0368e20>] (regmap_irq_thread+0x17c/0x300)
[   99.492120] [<c0368e20>] (regmap_irq_thread) from [<c008ff20>] (irq_thread_fn+0x1c/0x40)
[   99.500586] [<c008ff20>] (irq_thread_fn) from [<c0090238>] (irq_thread+0x12c/0x188)
[   99.508600] [<c0090238>] (irq_thread) from [<c005f6f0>] (kthread+0xd4/0xf0)
[   99.515882] [<c005f6f0>] (kthread) from [<c000e3c8>] (ret_from_fork+0x14/0x2c)
[   99.523534] palmas-usb palmas_usb.7: USB cable is attached

Again, another sign that this was not tested! That is caused by the same
commit. It seems like you want *all* extcon users to call
devm_extcon_dev_allocate() but you didn't fix palmas to do that, I
suspect a few other drivers are missing that patch too.

Here's the change for palmas:

From: Felipe Balbi <balbi@ti.com>
Subject: extcon: palmas: fix regression on extcon-next

All extcon users must rely on devm_extcon_dev_allocate() otherwise
device registration will fail.

Signed-of-by: Felipe Balbi <balbi@ti.com>
---

diff --git a/drivers/extcon/extcon-palmas.c b/drivers/extcon/extcon-palmas.c
index 1a770e0..23a20d9 100644
--- a/drivers/extcon/extcon-palmas.c
+++ b/drivers/extcon/extcon-palmas.c
@@ -57,7 +57,7 @@  static irqreturn_t palmas_vbus_irq_handler(int irq, void *_palmas_usb)
 	if (vbus_line_state & PALMAS_INT3_LINE_STATE_VBUS) {
 		if (palmas_usb->linkstat != PALMAS_USB_STATE_VBUS) {
 			palmas_usb->linkstat = PALMAS_USB_STATE_VBUS;
-			extcon_set_cable_state(&palmas_usb->edev, "USB", true);
+			extcon_set_cable_state(palmas_usb->edev, "USB", true);
 			dev_info(palmas_usb->dev, "USB cable is attached\n");
 		} else {
 			dev_dbg(palmas_usb->dev,
@@ -66,7 +66,7 @@  static irqreturn_t palmas_vbus_irq_handler(int irq, void *_palmas_usb)
 	} else if (!(vbus_line_state & PALMAS_INT3_LINE_STATE_VBUS)) {
 		if (palmas_usb->linkstat == PALMAS_USB_STATE_VBUS) {
 			palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
-			extcon_set_cable_state(&palmas_usb->edev, "USB", false);
+			extcon_set_cable_state(palmas_usb->edev, "USB", false);
 			dev_info(palmas_usb->dev, "USB cable is detached\n");
 		} else {
 			dev_dbg(palmas_usb->dev,
@@ -93,7 +93,7 @@  static irqreturn_t palmas_id_irq_handler(int irq, void *_palmas_usb)
 			PALMAS_USB_ID_INT_LATCH_CLR,
 			PALMAS_USB_ID_INT_EN_HI_CLR_ID_GND);
 		palmas_usb->linkstat = PALMAS_USB_STATE_ID;
-		extcon_set_cable_state(&palmas_usb->edev, "USB-HOST", true);
+		extcon_set_cable_state(palmas_usb->edev, "USB-HOST", true);
 		dev_info(palmas_usb->dev, "USB-HOST cable is attached\n");
 	} else if ((set & PALMAS_USB_ID_INT_SRC_ID_FLOAT) &&
 				(id_src & PALMAS_USB_ID_INT_SRC_ID_FLOAT)) {
@@ -101,17 +101,17 @@  static irqreturn_t palmas_id_irq_handler(int irq, void *_palmas_usb)
 			PALMAS_USB_ID_INT_LATCH_CLR,
 			PALMAS_USB_ID_INT_EN_HI_CLR_ID_FLOAT);
 		palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
-		extcon_set_cable_state(&palmas_usb->edev, "USB-HOST", false);
+		extcon_set_cable_state(palmas_usb->edev, "USB-HOST", false);
 		dev_info(palmas_usb->dev, "USB-HOST cable is detached\n");
 	} else if ((palmas_usb->linkstat == PALMAS_USB_STATE_ID) &&
 				(!(set & PALMAS_USB_ID_INT_SRC_ID_GND))) {
 		palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
-		extcon_set_cable_state(&palmas_usb->edev, "USB-HOST", false);
+		extcon_set_cable_state(palmas_usb->edev, "USB-HOST", false);
 		dev_info(palmas_usb->dev, "USB-HOST cable is detached\n");
 	} else if ((palmas_usb->linkstat == PALMAS_USB_STATE_DISCONNECT) &&
 				(id_src & PALMAS_USB_ID_INT_SRC_ID_GND)) {
 		palmas_usb->linkstat = PALMAS_USB_STATE_ID;
-		extcon_set_cable_state(&palmas_usb->edev, "USB-HOST", true);
+		extcon_set_cable_state(palmas_usb->edev, "USB-HOST", true);
 		dev_info(palmas_usb->dev, " USB-HOST cable is attached\n");
 	}
 
@@ -187,15 +187,19 @@  static int palmas_usb_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, palmas_usb);
 
-	palmas_usb->edev.supported_cable = palmas_extcon_cable;
-	palmas_usb->edev.dev.parent = palmas_usb->dev;
-	palmas_usb->edev.name = kstrdup(node->name, GFP_KERNEL);
-	palmas_usb->edev.mutually_exclusive = mutually_exclusive;
+	palmas_usb->edev = devm_extcon_dev_allocate(&pdev->dev, palmas_extcon_cable);
+	if (!palmas_usb->edev) {
+		dev_err(&pdev->dev, "failed to allocate extcon_device\n");
+		return -ENOMEM;
+	}
+	palmas_usb->edev->dev.parent = palmas_usb->dev;
+	palmas_usb->edev->name = kstrdup(node->name, GFP_KERNEL);
+	palmas_usb->edev->mutually_exclusive = mutually_exclusive;
 
-	status = devm_extcon_dev_register(&pdev->dev, &palmas_usb->edev);
+	status = devm_extcon_dev_register(&pdev->dev, palmas_usb->edev);
 	if (status) {
 		dev_err(&pdev->dev, "failed to register extcon device\n");
-		kfree(palmas_usb->edev.name);
+		kfree(palmas_usb->edev->name);
 		return status;
 	}
 
@@ -209,7 +213,7 @@  static int palmas_usb_probe(struct platform_device *pdev)
 		if (status < 0) {
 			dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
 					palmas_usb->id_irq, status);
-			kfree(palmas_usb->edev.name);
+			kfree(palmas_usb->edev->name);
 			return status;
 		}
 	}
@@ -224,7 +228,7 @@  static int palmas_usb_probe(struct platform_device *pdev)
 		if (status < 0) {
 			dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
 					palmas_usb->vbus_irq, status);
-			kfree(palmas_usb->edev.name);
+			kfree(palmas_usb->edev->name);
 			return status;
 		}
 	}
@@ -238,7 +242,7 @@  static int palmas_usb_remove(struct platform_device *pdev)
 {
 	struct palmas_usb *palmas_usb = platform_get_drvdata(pdev);
 
-	kfree(palmas_usb->edev.name);
+	kfree(palmas_usb->edev->name);
 
 	return 0;
 }
diff --git a/include/linux/mfd/palmas.h b/include/linux/mfd/palmas.h
index 9974e38..b8f87b7 100644
--- a/include/linux/mfd/palmas.h
+++ b/include/linux/mfd/palmas.h
@@ -415,7 +415,7 @@  struct palmas_usb {
 	struct palmas *palmas;
 	struct device *dev;
 
-	struct extcon_dev edev;
+	struct extcon_dev *edev;
 
 	int id_otg_irq;
 	int id_irq;