diff mbox series

usb: dwc2: Fix error path in gadget registration

Message ID 20200714084800.11340-1-m.szyprowski@samsung.com
State New
Headers show
Series usb: dwc2: Fix error path in gadget registration | expand

Commit Message

Marek Szyprowski July 14, 2020, 8:48 a.m. UTC
When gadget registration fails, one should not call usb_del_gadget_udc().
Ensure this by setting gadget->udc to NULL. Also in case of a failure
there is no need to disable low-level hardware, so return immiedetly
instead of jumping to error_init label.

This fixes the following kernel NULL ptr dereference on gadget failure
(can be easily triggered with g_mass_storage without any module
parameters):

dwc2 12480000.hsotg: dwc2_check_params: Invalid parameter besl=1
dwc2 12480000.hsotg: dwc2_check_params: Invalid parameter g_np_tx_fifo_size=1024
dwc2 12480000.hsotg: EPs: 16, dedicated fifos, 7808 entries in SPRAM
Mass Storage Function, version: 2009/09/11
LUN: removable file: (no medium)
no file given for LUN0
g_mass_storage 12480000.hsotg: failed to start g_mass_storage: -22
8<--- cut here ---
Unable to handle kernel NULL pointer dereference at virtual address 00000104
pgd = (ptrval)
[00000104] *pgd=00000000
Internal error: Oops: 805 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.8.0-rc5 #3133
Hardware name: Samsung Exynos (Flattened Device Tree)
Workqueue: events deferred_probe_work_func
PC is at usb_del_gadget_udc+0x38/0xc4
LR is at __mutex_lock+0x31c/0xb18
...
Process kworker/0:1 (pid: 12, stack limit = 0x(ptrval))
Stack: (0xef121db0 to 0xef122000)
...
[<c076bf3c>] (usb_del_gadget_udc) from [<c0726bec>] (dwc2_hsotg_remove+0x10/0x20)
[<c0726bec>] (dwc2_hsotg_remove) from [<c0711208>] (dwc2_driver_probe+0x57c/0x69c)
[<c0711208>] (dwc2_driver_probe) from [<c06247c0>] (platform_drv_probe+0x6c/0xa4)
[<c06247c0>] (platform_drv_probe) from [<c0621df4>] (really_probe+0x200/0x48c)
[<c0621df4>] (really_probe) from [<c06221e8>] (driver_probe_device+0x78/0x1fc)
[<c06221e8>] (driver_probe_device) from [<c061fcd4>] (bus_for_each_drv+0x74/0xb8)
[<c061fcd4>] (bus_for_each_drv) from [<c0621b54>] (__device_attach+0xd4/0x16c)
[<c0621b54>] (__device_attach) from [<c0620c98>] (bus_probe_device+0x88/0x90)
[<c0620c98>] (bus_probe_device) from [<c06211b0>] (deferred_probe_work_func+0x3c/0xd0)
[<c06211b0>] (deferred_probe_work_func) from [<c0149280>] (process_one_work+0x234/0x7dc)
[<c0149280>] (process_one_work) from [<c014986c>] (worker_thread+0x44/0x51c)
[<c014986c>] (worker_thread) from [<c0150b1c>] (kthread+0x158/0x1a0)
[<c0150b1c>] (kthread) from [<c0100114>] (ret_from_fork+0x14/0x20)
Exception stack(0xef121fb0 to 0xef121ff8)
...
---[ end trace 9724c2fc7cc9c982 ]---

Fixes: 207324a321a8 ("usb: dwc2: Postponed gadget registration to the udc class driver")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

---
 drivers/usb/dwc2/platform.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

-- 
2.17.1

Comments

Minas Harutyunyan July 14, 2020, 12:32 p.m. UTC | #1
Hi Marek,

On 7/14/2020 12:48 PM, Marek Szyprowski wrote:
> When gadget registration fails, one should not call usb_del_gadget_udc().

> Ensure this by setting gadget->udc to NULL. Also in case of a failure

I was able to reproduce issue. I'm Ok with this fix.

> there is no need to disable low-level hardware, so return immiedetly

> instead of jumping to error_init label.

> 

Why do you think that disable low-level hardware not required which was 
enabled before? Also for some platforms required to call 
regulator_disable() which was enabled earlier in probe function.
So, I suggest to keep jump to error_init label.

> This fixes the following kernel NULL ptr dereference on gadget failure

> (can be easily triggered with g_mass_storage without any module

> parameters):

> 


Thanks,
Minas
Marek Szyprowski July 15, 2020, 8:42 a.m. UTC | #2
Hi Minas,

On 14.07.2020 14:32, Minas Harutyunyan wrote:
> On 7/14/2020 12:48 PM, Marek Szyprowski wrote:

>> When gadget registration fails, one should not call usb_del_gadget_udc().

>> Ensure this by setting gadget->udc to NULL. Also in case of a failure

> I was able to reproduce issue. I'm Ok with this fix.

>

>> there is no need to disable low-level hardware, so return immiedetly

>> instead of jumping to error_init label.

>>

> Why do you think that disable low-level hardware not required which was

> enabled before? Also for some platforms required to call

> regulator_disable() which was enabled earlier in probe function.

> So, I suggest to keep jump to error_init label.


If I keep the jump to error_init label, then there is unbalanced call to 
dwc2_lowlevel_hw_disable(). usb_add_gadget_udc() can fail in 2 places: 
on gadget->bind() or during udc_start(). In the first case, the HW was 
not yet enabled, so there is no need to disable it. In the latter one, 
the error might be returned only from the dwc2_lowlevel_hw_enable(), so 
again there is no need to call dwc2_lowlevel_hw_disable().

If I keep the "goto error_init;" line, I get the following errors:

dwc2 12480000.hsotg: dwc2_check_params: Invalid parameter besl=1
dwc2 12480000.hsotg: dwc2_check_params: Invalid parameter 
g_np_tx_fifo_size=1024
dwc2 12480000.hsotg: EPs: 16, dedicated fifos, 7808 entries in SPRAM
Mass Storage Function, version: 2009/09/11
LUN: removable file: (no medium)
no file given for LUN0
g_mass_storage 12480000.hsotg: failed to start g_mass_storage: -22
------------[ cut here ]------------
WARNING: CPU: 3 PID: 49 at drivers/clk/clk.c:958 
clk_core_disable+0x1e4/0x314
usb_device already disabled
Modules linked in:
CPU: 3 PID: 49 Comm: kworker/3:1 Not tainted 
5.8.0-rc5-next-20200714-00003-g105f360ba595-dirty #8758
Hardware name: Samsung Exynos (Flattened Device Tree)
Workqueue: events deferred_probe_work_func
[<c011184c>] (unwind_backtrace) from [<c010d250>] (show_stack+0x10/0x14)
[<c010d250>] (show_stack) from [<c051b8fc>] (dump_stack+0xbc/0xe8)
[<c051b8fc>] (dump_stack) from [<c0126ed8>] (__warn+0xf0/0x108)
[<c0126ed8>] (__warn) from [<c0126f64>] (warn_slowpath_fmt+0x74/0xb8)
[<c0126f64>] (warn_slowpath_fmt) from [<c056c338>] 
(clk_core_disable+0x1e4/0x314)
[<c056c338>] (clk_core_disable) from [<c056c480>] 
(clk_core_disable_lock+0x18/0x24)
[<c056c480>] (clk_core_disable_lock) from [<c073f9d4>] 
(__dwc2_lowlevel_hw_disable+0x3c/0xa0)
[<c073f9d4>] (__dwc2_lowlevel_hw_disable) from [<c0740188>] 
(dwc2_driver_probe+0x2d4/0x6ac)
[<c0740188>] (dwc2_driver_probe) from [<c0653640>] 
(platform_drv_probe+0x6c/0xa4)
[<c0653640>] (platform_drv_probe) from [<c0650bdc>] 
(really_probe+0x200/0x4fc)
[<c0650bdc>] (really_probe) from [<c0651040>] 
(driver_probe_device+0x78/0x1fc)
[<c0651040>] (driver_probe_device) from [<c064ea78>] 
(bus_for_each_drv+0x74/0xb8)
[<c064ea78>] (bus_for_each_drv) from [<c065093c>] 
(__device_attach+0xd4/0x16c)
[<c065093c>] (__device_attach) from [<c064fa3c>] 
(bus_probe_device+0x88/0x90)
[<c064fa3c>] (bus_probe_device) from [<c064ff54>] 
(deferred_probe_work_func+0x3c/0xd0)
[<c064ff54>] (deferred_probe_work_func) from [<c0148a5c>] 
(process_one_work+0x234/0x7dc)
[<c0148a5c>] (process_one_work) from [<c0149048>] (worker_thread+0x44/0x51c)
[<c0149048>] (worker_thread) from [<c015039c>] (kthread+0x158/0x1a0)
[<c015039c>] (kthread) from [<c0100114>] (ret_from_fork+0x14/0x20)
Exception stack(0xee923fb0 to 0xee923ff8)
...
irq event stamp: 36966
hardirqs last  enabled at (36965): [<c02b92d8>] kfree+0x1a4/0x3f0
hardirqs last disabled at (36966): [<c0569edc>] clk_enable_lock+0x14/0x134
softirqs last  enabled at (36814): [<c010174c>] __do_softirq+0x50c/0x608
softirqs last disabled at (36803): [<c0130218>] irq_exit+0x168/0x16c
---[ end trace f55f4b28f3080c12 ]---
------------[ cut here ]------------
WARNING: CPU: 3 PID: 49 at drivers/clk/clk.c:817 
clk_core_unprepare+0x33c/0x470
usb_device already unprepared
Modules linked in:
CPU: 3 PID: 49 Comm: kworker/3:1 Tainted: G        W 
5.8.0-rc5-next-20200714-00003-g105f360ba595-dirty #8758
Hardware name: Samsung Exynos (Flattened Device Tree)
Workqueue: events deferred_probe_work_func
[<c011184c>] (unwind_backtrace) from [<c010d250>] (show_stack+0x10/0x14)
[<c010d250>] (show_stack) from [<c051b8fc>] (dump_stack+0xbc/0xe8)
[<c051b8fc>] (dump_stack) from [<c0126ed8>] (__warn+0xf0/0x108)
[<c0126ed8>] (__warn) from [<c0126f64>] (warn_slowpath_fmt+0x74/0xb8)
[<c0126f64>] (warn_slowpath_fmt) from [<c056dcb8>] 
(clk_core_unprepare+0x33c/0x470)
[<c056dcb8>] (clk_core_unprepare) from [<c056de10>] 
(clk_unprepare+0x24/0x2c)
[<c056de10>] (clk_unprepare) from [<c073f9dc>] 
(__dwc2_lowlevel_hw_disable+0x44/0xa0)
[<c073f9dc>] (__dwc2_lowlevel_hw_disable) from [<c0740188>] 
(dwc2_driver_probe+0x2d4/0x6ac)
[<c0740188>] (dwc2_driver_probe) from [<c0653640>] 
(platform_drv_probe+0x6c/0xa4)
[<c0653640>] (platform_drv_probe) from [<c0650bdc>] 
(really_probe+0x200/0x4fc)
[<c0650bdc>] (really_probe) from [<c0651040>] 
(driver_probe_device+0x78/0x1fc)
[<c0651040>] (driver_probe_device) from [<c064ea78>] 
(bus_for_each_drv+0x74/0xb8)
[<c064ea78>] (bus_for_each_drv) from [<c065093c>] 
(__device_attach+0xd4/0x16c)
[<c065093c>] (__device_attach) from [<c064fa3c>] 
(bus_probe_device+0x88/0x90)
[<c064fa3c>] (bus_probe_device) from [<c064ff54>] 
(deferred_probe_work_func+0x3c/0xd0)
[<c064ff54>] (deferred_probe_work_func) from [<c0148a5c>] 
(process_one_work+0x234/0x7dc)
[<c0148a5c>] (process_one_work) from [<c0149048>] (worker_thread+0x44/0x51c)
[<c0149048>] (worker_thread) from [<c015039c>] (kthread+0x158/0x1a0)
[<c015039c>] (kthread) from [<c0100114>] (ret_from_fork+0x14/0x20)
Exception stack(0xee923fb0 to 0xee923ff8)
...
irq event stamp: 37073
hardirqs last  enabled at (37081): [<c019d624>] console_unlock+0x430/0x6cc
hardirqs last disabled at (37108): [<c019d348>] console_unlock+0x154/0x6cc
softirqs last  enabled at (37124): [<c010174c>] __do_softirq+0x50c/0x608
softirqs last disabled at (37135): [<c0130218>] irq_exit+0x168/0x16c
---[ end trace f55f4b28f3080c13 ]---
------------[ cut here ]------------
WARNING: CPU: 3 PID: 49 at drivers/regulator/core.c:2603 
_regulator_disable+0x180/0x1d8
unbalanced disables for VUOTG_3.0V
Modules linked in:
CPU: 3 PID: 49 Comm: kworker/3:1 Tainted: G        W 
5.8.0-rc5-next-20200714-00003-g105f360ba595-dirty #8758
Hardware name: Samsung Exynos (Flattened Device Tree)
Workqueue: events deferred_probe_work_func
[<c011184c>] (unwind_backtrace) from [<c010d250>] (show_stack+0x10/0x14)
[<c010d250>] (show_stack) from [<c051b8fc>] (dump_stack+0xbc/0xe8)
[<c051b8fc>] (dump_stack) from [<c0126ed8>] (__warn+0xf0/0x108)
[<c0126ed8>] (__warn) from [<c0126f64>] (warn_slowpath_fmt+0x74/0xb8)
[<c0126f64>] (warn_slowpath_fmt) from [<c0585e78>] 
(_regulator_disable+0x180/0x1d8)
[<c0585e78>] (_regulator_disable) from [<c0585f04>] 
(regulator_disable+0x34/0xe0)
[<c0585f04>] (regulator_disable) from [<c0587ef8>] 
(regulator_bulk_disable+0x28/0xb0)
[<c0587ef8>] (regulator_bulk_disable) from [<c0740188>] 
(dwc2_driver_probe+0x2d4/0x6ac)
[<c0740188>] (dwc2_driver_probe) from [<c0653640>] 
(platform_drv_probe+0x6c/0xa4)
[<c0653640>] (platform_drv_probe) from [<c0650bdc>] 
(really_probe+0x200/0x4fc)
[<c0650bdc>] (really_probe) from [<c0651040>] 
(driver_probe_device+0x78/0x1fc)
[<c0651040>] (driver_probe_device) from [<c064ea78>] 
(bus_for_each_drv+0x74/0xb8)
[<c064ea78>] (bus_for_each_drv) from [<c065093c>] 
(__device_attach+0xd4/0x16c)
[<c065093c>] (__device_attach) from [<c064fa3c>] 
(bus_probe_device+0x88/0x90)
[<c064fa3c>] (bus_probe_device) from [<c064ff54>] 
(deferred_probe_work_func+0x3c/0xd0)
[<c064ff54>] (deferred_probe_work_func) from [<c0148a5c>] 
(process_one_work+0x234/0x7dc)
[<c0148a5c>] (process_one_work) from [<c0149048>] (worker_thread+0x44/0x51c)
[<c0149048>] (worker_thread) from [<c015039c>] (kthread+0x158/0x1a0)
[<c015039c>] (kthread) from [<c0100114>] (ret_from_fork+0x14/0x20)
Exception stack(0xee923fb0 to 0xee923ff8)
...
irq event stamp: 37243
hardirqs last  enabled at (37251): [<c019d624>] console_unlock+0x430/0x6cc
hardirqs last disabled at (37274): [<c0ac0790>] __schedule+0xd8/0x860
softirqs last  enabled at (37270): [<c010174c>] __do_softirq+0x50c/0x608
softirqs last disabled at (37291): [<c0130218>] irq_exit+0x168/0x16c
---[ end trace f55f4b28f3080c14 ]---
Failed to disable vusb_a: -5
dwc2: probe of 12480000.hsotg failed with error -22
8<--- cut here ---
Unable to handle kernel NULL pointer dereference at virtual address 00000004
pgd = (ptrval)
[00000004] *pgd=00000000
Internal error: Oops: 5 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 3 PID: 87 Comm: kworker/3:2 Tainted: G        W 
5.8.0-rc5-next-20200714-00003-g105f360ba595-dirty #8758
Hardware name: Samsung Exynos (Flattened Device Tree)
Workqueue:  0x0 (rcu_gp)
PC is at process_one_work+0x44/0x7dc
LR is at 0xedc226d0
...
Process kworker/3:2 (pid: 87, stack limit = 0x(ptrval))
Stack: (0xeda03f00 to 0xeda04000)
...
[<c014886c>] (process_one_work) from [<c0149048>] (worker_thread+0x44/0x51c)
[<c0149048>] (worker_thread) from [<c015039c>] (kthread+0x158/0x1a0)
[<c015039c>] (kthread) from [<c0100114>] (ret_from_fork+0x14/0x20)
Exception stack(0xeda03fb0 to 0xeda03ff8)
...
---[ end trace f55f4b28f3080c15 ]---
note: kworker/3:2[87] exited with preempt_count 1

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland
Minas Harutyunyan July 15, 2020, 1:54 p.m. UTC | #3
Hi Marek,

On 7/15/2020 12:42 PM, Marek Szyprowski wrote:
> Hi Minas,

> 

> On 14.07.2020 14:32, Minas Harutyunyan wrote:

>> On 7/14/2020 12:48 PM, Marek Szyprowski wrote:

>>> When gadget registration fails, one should not call usb_del_gadget_udc().

>>> Ensure this by setting gadget->udc to NULL. Also in case of a failure

>> I was able to reproduce issue. I'm Ok with this fix.

>>

>>> there is no need to disable low-level hardware, so return immiedetly

>>> instead of jumping to error_init label.

>>>

>> Why do you think that disable low-level hardware not required which was

>> enabled before? Also for some platforms required to call

>> regulator_disable() which was enabled earlier in probe function.

>> So, I suggest to keep jump to error_init label.

> 

> If I keep the jump to error_init label, then there is unbalanced call to

> dwc2_lowlevel_hw_disable(). usb_add_gadget_udc() can fail in 2 places:

> on gadget->bind() or during udc_start(). In the first case, the HW was

> not yet enabled, so there is no need to disable it. In the latter one,

> the error might be returned only from the dwc2_lowlevel_hw_enable(), so

> again there is no need to call dwc2_lowlevel_hw_disable().

> 

> If I keep the "goto error_init;" line, I get the following errors:

> 

> dwc2 12480000.hsotg: dwc2_check_params: Invalid parameter besl=1

> dwc2 12480000.hsotg: dwc2_check_params: Invalid parameter

> g_np_tx_fifo_size=1024

> dwc2 12480000.hsotg: EPs: 16, dedicated fifos, 7808 entries in SPRAM

> Mass Storage Function, version: 2009/09/11

> LUN: removable file: (no medium)

> no file given for LUN0

> g_mass_storage 12480000.hsotg: failed to start g_mass_storage: -22

> ------------[ cut here ]------------

> WARNING: CPU: 3 PID: 49 at drivers/clk/clk.c:958

> clk_core_disable+0x1e4/0x314

> usb_device already disabled

> Modules linked in:

> CPU: 3 PID: 49 Comm: kworker/3:1 Not tainted

> 5.8.0-rc5-next-20200714-00003-g105f360ba595-dirty #8758

> Hardware name: Samsung Exynos (Flattened Device Tree)

> Workqueue: events deferred_probe_work_func

> [<c011184c>] (unwind_backtrace) from [<c010d250>] (show_stack+0x10/0x14)

> [<c010d250>] (show_stack) from [<c051b8fc>] (dump_stack+0xbc/0xe8)

> [<c051b8fc>] (dump_stack) from [<c0126ed8>] (__warn+0xf0/0x108)

> [<c0126ed8>] (__warn) from [<c0126f64>] (warn_slowpath_fmt+0x74/0xb8)

> [<c0126f64>] (warn_slowpath_fmt) from [<c056c338>]

> (clk_core_disable+0x1e4/0x314)

> [<c056c338>] (clk_core_disable) from [<c056c480>]

> (clk_core_disable_lock+0x18/0x24)

> [<c056c480>] (clk_core_disable_lock) from [<c073f9d4>]

> (__dwc2_lowlevel_hw_disable+0x3c/0xa0)

> [<c073f9d4>] (__dwc2_lowlevel_hw_disable) from [<c0740188>]

> (dwc2_driver_probe+0x2d4/0x6ac)

> [<c0740188>] (dwc2_driver_probe) from [<c0653640>]

> (platform_drv_probe+0x6c/0xa4)

> [<c0653640>] (platform_drv_probe) from [<c0650bdc>]

> (really_probe+0x200/0x4fc)

> [<c0650bdc>] (really_probe) from [<c0651040>]

> (driver_probe_device+0x78/0x1fc)

> [<c0651040>] (driver_probe_device) from [<c064ea78>]

> (bus_for_each_drv+0x74/0xb8)

> [<c064ea78>] (bus_for_each_drv) from [<c065093c>]

> (__device_attach+0xd4/0x16c)

> [<c065093c>] (__device_attach) from [<c064fa3c>]

> (bus_probe_device+0x88/0x90)

> [<c064fa3c>] (bus_probe_device) from [<c064ff54>]

> (deferred_probe_work_func+0x3c/0xd0)

> [<c064ff54>] (deferred_probe_work_func) from [<c0148a5c>]

> (process_one_work+0x234/0x7dc)

> [<c0148a5c>] (process_one_work) from [<c0149048>] (worker_thread+0x44/0x51c)

> [<c0149048>] (worker_thread) from [<c015039c>] (kthread+0x158/0x1a0)

> [<c015039c>] (kthread) from [<c0100114>] (ret_from_fork+0x14/0x20)

> Exception stack(0xee923fb0 to 0xee923ff8)

> ...

> irq event stamp: 36966

> hardirqs last  enabled at (36965): [<c02b92d8>] kfree+0x1a4/0x3f0

> hardirqs last disabled at (36966): [<c0569edc>] clk_enable_lock+0x14/0x134

> softirqs last  enabled at (36814): [<c010174c>] __do_softirq+0x50c/0x608

> softirqs last disabled at (36803): [<c0130218>] irq_exit+0x168/0x16c

> ---[ end trace f55f4b28f3080c12 ]---

> ------------[ cut here ]------------

> WARNING: CPU: 3 PID: 49 at drivers/clk/clk.c:817

> clk_core_unprepare+0x33c/0x470

> usb_device already unprepared

> Modules linked in:

> CPU: 3 PID: 49 Comm: kworker/3:1 Tainted: G        W

> 5.8.0-rc5-next-20200714-00003-g105f360ba595-dirty #8758

> Hardware name: Samsung Exynos (Flattened Device Tree)

> Workqueue: events deferred_probe_work_func

> [<c011184c>] (unwind_backtrace) from [<c010d250>] (show_stack+0x10/0x14)

> [<c010d250>] (show_stack) from [<c051b8fc>] (dump_stack+0xbc/0xe8)

> [<c051b8fc>] (dump_stack) from [<c0126ed8>] (__warn+0xf0/0x108)

> [<c0126ed8>] (__warn) from [<c0126f64>] (warn_slowpath_fmt+0x74/0xb8)

> [<c0126f64>] (warn_slowpath_fmt) from [<c056dcb8>]

> (clk_core_unprepare+0x33c/0x470)

> [<c056dcb8>] (clk_core_unprepare) from [<c056de10>]

> (clk_unprepare+0x24/0x2c)

> [<c056de10>] (clk_unprepare) from [<c073f9dc>]

> (__dwc2_lowlevel_hw_disable+0x44/0xa0)

> [<c073f9dc>] (__dwc2_lowlevel_hw_disable) from [<c0740188>]

> (dwc2_driver_probe+0x2d4/0x6ac)

> [<c0740188>] (dwc2_driver_probe) from [<c0653640>]

> (platform_drv_probe+0x6c/0xa4)

> [<c0653640>] (platform_drv_probe) from [<c0650bdc>]

> (really_probe+0x200/0x4fc)

> [<c0650bdc>] (really_probe) from [<c0651040>]

> (driver_probe_device+0x78/0x1fc)

> [<c0651040>] (driver_probe_device) from [<c064ea78>]

> (bus_for_each_drv+0x74/0xb8)

> [<c064ea78>] (bus_for_each_drv) from [<c065093c>]

> (__device_attach+0xd4/0x16c)

> [<c065093c>] (__device_attach) from [<c064fa3c>]

> (bus_probe_device+0x88/0x90)

> [<c064fa3c>] (bus_probe_device) from [<c064ff54>]

> (deferred_probe_work_func+0x3c/0xd0)

> [<c064ff54>] (deferred_probe_work_func) from [<c0148a5c>]

> (process_one_work+0x234/0x7dc)

> [<c0148a5c>] (process_one_work) from [<c0149048>] (worker_thread+0x44/0x51c)

> [<c0149048>] (worker_thread) from [<c015039c>] (kthread+0x158/0x1a0)

> [<c015039c>] (kthread) from [<c0100114>] (ret_from_fork+0x14/0x20)

> Exception stack(0xee923fb0 to 0xee923ff8)

> ...

> irq event stamp: 37073

> hardirqs last  enabled at (37081): [<c019d624>] console_unlock+0x430/0x6cc

> hardirqs last disabled at (37108): [<c019d348>] console_unlock+0x154/0x6cc

> softirqs last  enabled at (37124): [<c010174c>] __do_softirq+0x50c/0x608

> softirqs last disabled at (37135): [<c0130218>] irq_exit+0x168/0x16c

> ---[ end trace f55f4b28f3080c13 ]---

> ------------[ cut here ]------------

> WARNING: CPU: 3 PID: 49 at drivers/regulator/core.c:2603

> _regulator_disable+0x180/0x1d8

> unbalanced disables for VUOTG_3.0V

> Modules linked in:

> CPU: 3 PID: 49 Comm: kworker/3:1 Tainted: G        W

> 5.8.0-rc5-next-20200714-00003-g105f360ba595-dirty #8758

> Hardware name: Samsung Exynos (Flattened Device Tree)

> Workqueue: events deferred_probe_work_func

> [<c011184c>] (unwind_backtrace) from [<c010d250>] (show_stack+0x10/0x14)

> [<c010d250>] (show_stack) from [<c051b8fc>] (dump_stack+0xbc/0xe8)

> [<c051b8fc>] (dump_stack) from [<c0126ed8>] (__warn+0xf0/0x108)

> [<c0126ed8>] (__warn) from [<c0126f64>] (warn_slowpath_fmt+0x74/0xb8)

> [<c0126f64>] (warn_slowpath_fmt) from [<c0585e78>]

> (_regulator_disable+0x180/0x1d8)

> [<c0585e78>] (_regulator_disable) from [<c0585f04>]

> (regulator_disable+0x34/0xe0)

> [<c0585f04>] (regulator_disable) from [<c0587ef8>]

> (regulator_bulk_disable+0x28/0xb0)

> [<c0587ef8>] (regulator_bulk_disable) from [<c0740188>]

> (dwc2_driver_probe+0x2d4/0x6ac)

> [<c0740188>] (dwc2_driver_probe) from [<c0653640>]

> (platform_drv_probe+0x6c/0xa4)

> [<c0653640>] (platform_drv_probe) from [<c0650bdc>]

> (really_probe+0x200/0x4fc)

> [<c0650bdc>] (really_probe) from [<c0651040>]

> (driver_probe_device+0x78/0x1fc)

> [<c0651040>] (driver_probe_device) from [<c064ea78>]

> (bus_for_each_drv+0x74/0xb8)

> [<c064ea78>] (bus_for_each_drv) from [<c065093c>]

> (__device_attach+0xd4/0x16c)

> [<c065093c>] (__device_attach) from [<c064fa3c>]

> (bus_probe_device+0x88/0x90)

> [<c064fa3c>] (bus_probe_device) from [<c064ff54>]

> (deferred_probe_work_func+0x3c/0xd0)

> [<c064ff54>] (deferred_probe_work_func) from [<c0148a5c>]

> (process_one_work+0x234/0x7dc)

> [<c0148a5c>] (process_one_work) from [<c0149048>] (worker_thread+0x44/0x51c)

> [<c0149048>] (worker_thread) from [<c015039c>] (kthread+0x158/0x1a0)

> [<c015039c>] (kthread) from [<c0100114>] (ret_from_fork+0x14/0x20)

> Exception stack(0xee923fb0 to 0xee923ff8)

> ...

> irq event stamp: 37243

> hardirqs last  enabled at (37251): [<c019d624>] console_unlock+0x430/0x6cc

> hardirqs last disabled at (37274): [<c0ac0790>] __schedule+0xd8/0x860

> softirqs last  enabled at (37270): [<c010174c>] __do_softirq+0x50c/0x608

> softirqs last disabled at (37291): [<c0130218>] irq_exit+0x168/0x16c

> ---[ end trace f55f4b28f3080c14 ]---

> Failed to disable vusb_a: -5

> dwc2: probe of 12480000.hsotg failed with error -22

> 8<--- cut here ---

> Unable to handle kernel NULL pointer dereference at virtual address 00000004

> pgd = (ptrval)

> [00000004] *pgd=00000000

> Internal error: Oops: 5 [#1] PREEMPT SMP ARM

> Modules linked in:

> CPU: 3 PID: 87 Comm: kworker/3:2 Tainted: G        W

> 5.8.0-rc5-next-20200714-00003-g105f360ba595-dirty #8758

> Hardware name: Samsung Exynos (Flattened Device Tree)

> Workqueue:  0x0 (rcu_gp)

> PC is at process_one_work+0x44/0x7dc

> LR is at 0xedc226d0

> ...

> Process kworker/3:2 (pid: 87, stack limit = 0x(ptrval))

> Stack: (0xeda03f00 to 0xeda04000)

> ...

> [<c014886c>] (process_one_work) from [<c0149048>] (worker_thread+0x44/0x51c)

> [<c0149048>] (worker_thread) from [<c015039c>] (kthread+0x158/0x1a0)

> [<c015039c>] (kthread) from [<c0100114>] (ret_from_fork+0x14/0x20)

> Exception stack(0xeda03fb0 to 0xeda03ff8)

> ...

> ---[ end trace f55f4b28f3080c15 ]---

> note: kworker/3:2[87] exited with preempt_count 1

> 

> Best regards

> 


I guess you build driver in (hsotg->dr_mode == USB_DR_MODE_PERIPHERAL) 
and this is why call of dwc2_lowlevel_hw_disable() at 'error:' label 
create issue. Could you please test on your setup follow implementation:
...
error:
	if (hsotg->dr_mode != USB_DR_MODE_PERIPHERAL)
		dwc2_lowlevel_hw_disable(hsotg);
	return retval;
}
...

Thanks,
Minas
Marek Szyprowski July 16, 2020, 11:58 a.m. UTC | #4
Hi Minas,

On 15.07.2020 15:54, Minas Harutyunyan wrote:
> On 7/15/2020 12:42 PM, Marek Szyprowski wrote:

>> On 14.07.2020 14:32, Minas Harutyunyan wrote:

>>> On 7/14/2020 12:48 PM, Marek Szyprowski wrote:

>>>> When gadget registration fails, one should not call usb_del_gadget_udc().

>>>> Ensure this by setting gadget->udc to NULL. Also in case of a failure

>>> I was able to reproduce issue. I'm Ok with this fix.

>>>

>>>> there is no need to disable low-level hardware, so return immiedetly

>>>> instead of jumping to error_init label.

>>>>

>>> Why do you think that disable low-level hardware not required which was

>>> enabled before? Also for some platforms required to call

>>> regulator_disable() which was enabled earlier in probe function.

>>> So, I suggest to keep jump to error_init label.

>> If I keep the jump to error_init label, then there is unbalanced call to

>> dwc2_lowlevel_hw_disable(). usb_add_gadget_udc() can fail in 2 places:

>> on gadget->bind() or during udc_start(). In the first case, the HW was

>> not yet enabled, so there is no need to disable it. In the latter one,

>> the error might be returned only from the dwc2_lowlevel_hw_enable(), so

>> again there is no need to call dwc2_lowlevel_hw_disable().

>>

>> If I keep the "goto error_init;" line, I get the following errors:

>>

>> dwc2 12480000.hsotg: dwc2_check_params: Invalid parameter besl=1

>> dwc2 12480000.hsotg: dwc2_check_params: Invalid parameter

>> g_np_tx_fifo_size=1024

>> dwc2 12480000.hsotg: EPs: 16, dedicated fifos, 7808 entries in SPRAM

>> Mass Storage Function, version: 2009/09/11

>> LUN: removable file: (no medium)

>> no file given for LUN0

>> g_mass_storage 12480000.hsotg: failed to start g_mass_storage: -22

>> ------------[ cut here ]------------

>> WARNING: CPU: 3 PID: 49 at drivers/clk/clk.c:958

>> clk_core_disable+0x1e4/0x314

>> usb_device already disabled

>> Modules linked in:

>> CPU: 3 PID: 49 Comm: kworker/3:1 Not tainted

>> 5.8.0-rc5-next-20200714-00003-g105f360ba595-dirty #8758

>> Hardware name: Samsung Exynos (Flattened Device Tree)

>> Workqueue: events deferred_probe_work_func

>> [<c011184c>] (unwind_backtrace) from [<c010d250>] (show_stack+0x10/0x14)

>> [<c010d250>] (show_stack) from [<c051b8fc>] (dump_stack+0xbc/0xe8)

>> [<c051b8fc>] (dump_stack) from [<c0126ed8>] (__warn+0xf0/0x108)

>> [<c0126ed8>] (__warn) from [<c0126f64>] (warn_slowpath_fmt+0x74/0xb8)

>> [<c0126f64>] (warn_slowpath_fmt) from [<c056c338>]

>> (clk_core_disable+0x1e4/0x314)

>> [<c056c338>] (clk_core_disable) from [<c056c480>]

>> (clk_core_disable_lock+0x18/0x24)

>> [<c056c480>] (clk_core_disable_lock) from [<c073f9d4>]

>> (__dwc2_lowlevel_hw_disable+0x3c/0xa0)

>> [<c073f9d4>] (__dwc2_lowlevel_hw_disable) from [<c0740188>]

>> (dwc2_driver_probe+0x2d4/0x6ac)

>> [<c0740188>] (dwc2_driver_probe) from [<c0653640>]

>> (platform_drv_probe+0x6c/0xa4)

>> [<c0653640>] (platform_drv_probe) from [<c0650bdc>]

>> (really_probe+0x200/0x4fc)

>> [<c0650bdc>] (really_probe) from [<c0651040>]

>> (driver_probe_device+0x78/0x1fc)

>> [<c0651040>] (driver_probe_device) from [<c064ea78>]

>> (bus_for_each_drv+0x74/0xb8)

>> [<c064ea78>] (bus_for_each_drv) from [<c065093c>]

>> (__device_attach+0xd4/0x16c)

>> [<c065093c>] (__device_attach) from [<c064fa3c>]

>> (bus_probe_device+0x88/0x90)

>> [<c064fa3c>] (bus_probe_device) from [<c064ff54>]

>> (deferred_probe_work_func+0x3c/0xd0)

>> [<c064ff54>] (deferred_probe_work_func) from [<c0148a5c>]

>> (process_one_work+0x234/0x7dc)

>> [<c0148a5c>] (process_one_work) from [<c0149048>] (worker_thread+0x44/0x51c)

>> [<c0149048>] (worker_thread) from [<c015039c>] (kthread+0x158/0x1a0)

>> [<c015039c>] (kthread) from [<c0100114>] (ret_from_fork+0x14/0x20)

>> Exception stack(0xee923fb0 to 0xee923ff8)

>> ...

>> irq event stamp: 36966

>> hardirqs last  enabled at (36965): [<c02b92d8>] kfree+0x1a4/0x3f0

>> hardirqs last disabled at (36966): [<c0569edc>] clk_enable_lock+0x14/0x134

>> softirqs last  enabled at (36814): [<c010174c>] __do_softirq+0x50c/0x608

>> softirqs last disabled at (36803): [<c0130218>] irq_exit+0x168/0x16c

>> ---[ end trace f55f4b28f3080c12 ]---

>> ------------[ cut here ]------------

>> WARNING: CPU: 3 PID: 49 at drivers/clk/clk.c:817

>> clk_core_unprepare+0x33c/0x470

>> usb_device already unprepared

>> Modules linked in:

>> CPU: 3 PID: 49 Comm: kworker/3:1 Tainted: G        W

>> 5.8.0-rc5-next-20200714-00003-g105f360ba595-dirty #8758

>> Hardware name: Samsung Exynos (Flattened Device Tree)

>> Workqueue: events deferred_probe_work_func

>> [<c011184c>] (unwind_backtrace) from [<c010d250>] (show_stack+0x10/0x14)

>> [<c010d250>] (show_stack) from [<c051b8fc>] (dump_stack+0xbc/0xe8)

>> [<c051b8fc>] (dump_stack) from [<c0126ed8>] (__warn+0xf0/0x108)

>> [<c0126ed8>] (__warn) from [<c0126f64>] (warn_slowpath_fmt+0x74/0xb8)

>> [<c0126f64>] (warn_slowpath_fmt) from [<c056dcb8>]

>> (clk_core_unprepare+0x33c/0x470)

>> [<c056dcb8>] (clk_core_unprepare) from [<c056de10>]

>> (clk_unprepare+0x24/0x2c)

>> [<c056de10>] (clk_unprepare) from [<c073f9dc>]

>> (__dwc2_lowlevel_hw_disable+0x44/0xa0)

>> [<c073f9dc>] (__dwc2_lowlevel_hw_disable) from [<c0740188>]

>> (dwc2_driver_probe+0x2d4/0x6ac)

>> [<c0740188>] (dwc2_driver_probe) from [<c0653640>]

>> (platform_drv_probe+0x6c/0xa4)

>> [<c0653640>] (platform_drv_probe) from [<c0650bdc>]

>> (really_probe+0x200/0x4fc)

>> [<c0650bdc>] (really_probe) from [<c0651040>]

>> (driver_probe_device+0x78/0x1fc)

>> [<c0651040>] (driver_probe_device) from [<c064ea78>]

>> (bus_for_each_drv+0x74/0xb8)

>> [<c064ea78>] (bus_for_each_drv) from [<c065093c>]

>> (__device_attach+0xd4/0x16c)

>> [<c065093c>] (__device_attach) from [<c064fa3c>]

>> (bus_probe_device+0x88/0x90)

>> [<c064fa3c>] (bus_probe_device) from [<c064ff54>]

>> (deferred_probe_work_func+0x3c/0xd0)

>> [<c064ff54>] (deferred_probe_work_func) from [<c0148a5c>]

>> (process_one_work+0x234/0x7dc)

>> [<c0148a5c>] (process_one_work) from [<c0149048>] (worker_thread+0x44/0x51c)

>> [<c0149048>] (worker_thread) from [<c015039c>] (kthread+0x158/0x1a0)

>> [<c015039c>] (kthread) from [<c0100114>] (ret_from_fork+0x14/0x20)

>> Exception stack(0xee923fb0 to 0xee923ff8)

>> ...

>> irq event stamp: 37073

>> hardirqs last  enabled at (37081): [<c019d624>] console_unlock+0x430/0x6cc

>> hardirqs last disabled at (37108): [<c019d348>] console_unlock+0x154/0x6cc

>> softirqs last  enabled at (37124): [<c010174c>] __do_softirq+0x50c/0x608

>> softirqs last disabled at (37135): [<c0130218>] irq_exit+0x168/0x16c

>> ---[ end trace f55f4b28f3080c13 ]---

>> ------------[ cut here ]------------

>> WARNING: CPU: 3 PID: 49 at drivers/regulator/core.c:2603

>> _regulator_disable+0x180/0x1d8

>> unbalanced disables for VUOTG_3.0V

>> Modules linked in:

>> CPU: 3 PID: 49 Comm: kworker/3:1 Tainted: G        W

>> 5.8.0-rc5-next-20200714-00003-g105f360ba595-dirty #8758

>> Hardware name: Samsung Exynos (Flattened Device Tree)

>> Workqueue: events deferred_probe_work_func

>> [<c011184c>] (unwind_backtrace) from [<c010d250>] (show_stack+0x10/0x14)

>> [<c010d250>] (show_stack) from [<c051b8fc>] (dump_stack+0xbc/0xe8)

>> [<c051b8fc>] (dump_stack) from [<c0126ed8>] (__warn+0xf0/0x108)

>> [<c0126ed8>] (__warn) from [<c0126f64>] (warn_slowpath_fmt+0x74/0xb8)

>> [<c0126f64>] (warn_slowpath_fmt) from [<c0585e78>]

>> (_regulator_disable+0x180/0x1d8)

>> [<c0585e78>] (_regulator_disable) from [<c0585f04>]

>> (regulator_disable+0x34/0xe0)

>> [<c0585f04>] (regulator_disable) from [<c0587ef8>]

>> (regulator_bulk_disable+0x28/0xb0)

>> [<c0587ef8>] (regulator_bulk_disable) from [<c0740188>]

>> (dwc2_driver_probe+0x2d4/0x6ac)

>> [<c0740188>] (dwc2_driver_probe) from [<c0653640>]

>> (platform_drv_probe+0x6c/0xa4)

>> [<c0653640>] (platform_drv_probe) from [<c0650bdc>]

>> (really_probe+0x200/0x4fc)

>> [<c0650bdc>] (really_probe) from [<c0651040>]

>> (driver_probe_device+0x78/0x1fc)

>> [<c0651040>] (driver_probe_device) from [<c064ea78>]

>> (bus_for_each_drv+0x74/0xb8)

>> [<c064ea78>] (bus_for_each_drv) from [<c065093c>]

>> (__device_attach+0xd4/0x16c)

>> [<c065093c>] (__device_attach) from [<c064fa3c>]

>> (bus_probe_device+0x88/0x90)

>> [<c064fa3c>] (bus_probe_device) from [<c064ff54>]

>> (deferred_probe_work_func+0x3c/0xd0)

>> [<c064ff54>] (deferred_probe_work_func) from [<c0148a5c>]

>> (process_one_work+0x234/0x7dc)

>> [<c0148a5c>] (process_one_work) from [<c0149048>] (worker_thread+0x44/0x51c)

>> [<c0149048>] (worker_thread) from [<c015039c>] (kthread+0x158/0x1a0)

>> [<c015039c>] (kthread) from [<c0100114>] (ret_from_fork+0x14/0x20)

>> Exception stack(0xee923fb0 to 0xee923ff8)

>> ...

>> irq event stamp: 37243

>> hardirqs last  enabled at (37251): [<c019d624>] console_unlock+0x430/0x6cc

>> hardirqs last disabled at (37274): [<c0ac0790>] __schedule+0xd8/0x860

>> softirqs last  enabled at (37270): [<c010174c>] __do_softirq+0x50c/0x608

>> softirqs last disabled at (37291): [<c0130218>] irq_exit+0x168/0x16c

>> ---[ end trace f55f4b28f3080c14 ]---

>> Failed to disable vusb_a: -5

>> dwc2: probe of 12480000.hsotg failed with error -22

>> 8<--- cut here ---

>> Unable to handle kernel NULL pointer dereference at virtual address 00000004

>> pgd = (ptrval)

>> [00000004] *pgd=00000000

>> Internal error: Oops: 5 [#1] PREEMPT SMP ARM

>> Modules linked in:

>> CPU: 3 PID: 87 Comm: kworker/3:2 Tainted: G        W

>> 5.8.0-rc5-next-20200714-00003-g105f360ba595-dirty #8758

>> Hardware name: Samsung Exynos (Flattened Device Tree)

>> Workqueue:  0x0 (rcu_gp)

>> PC is at process_one_work+0x44/0x7dc

>> LR is at 0xedc226d0

>> ...

>> Process kworker/3:2 (pid: 87, stack limit = 0x(ptrval))

>> Stack: (0xeda03f00 to 0xeda04000)

>> ...

>> [<c014886c>] (process_one_work) from [<c0149048>] (worker_thread+0x44/0x51c)

>> [<c0149048>] (worker_thread) from [<c015039c>] (kthread+0x158/0x1a0)

>> [<c015039c>] (kthread) from [<c0100114>] (ret_from_fork+0x14/0x20)

>> Exception stack(0xeda03fb0 to 0xeda03ff8)

>> ...

>> ---[ end trace f55f4b28f3080c15 ]---

>> note: kworker/3:2[87] exited with preempt_count 1

>>

>> Best regards

>>

> I guess you build driver in (hsotg->dr_mode == USB_DR_MODE_PERIPHERAL)

> and this is why call of dwc2_lowlevel_hw_disable() at 'error:' label

> create issue. Could you please test on your setup follow implementation:

> ...

> error:

> 	if (hsotg->dr_mode != USB_DR_MODE_PERIPHERAL)

> 		dwc2_lowlevel_hw_disable(hsotg);

> 	return retval;

> }

> ...


Right, this will work. However, I would also change the order of 
operations - disabling usb33d regulator should be done after disabling 
lowlevel hardware to properly pair with the enable operations.

While playing with this I've also found an issue in UDC core:

https://lore.kernel.org/linux-usb/20200716115525.27519-1-m.szyprowski@samsung.com/T/#u

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland
Marek Szyprowski July 16, 2020, 12:03 p.m. UTC | #5
On 16.07.2020 13:58, Marek Szyprowski wrote:
> On 15.07.2020 15:54, Minas Harutyunyan wrote:

>> On 7/15/2020 12:42 PM, Marek Szyprowski wrote:

>>> On 14.07.2020 14:32, Minas Harutyunyan wrote:

>>>> On 7/14/2020 12:48 PM, Marek Szyprowski wrote:

>>>>> When gadget registration fails, one should not call 

>>>>> usb_del_gadget_udc().

>>>>> Ensure this by setting gadget->udc to NULL. Also in case of a failure

>>>> I was able to reproduce issue. I'm Ok with this fix.

>>>>

>>>>> there is no need to disable low-level hardware, so return immiedetly

>>>>> instead of jumping to error_init label.

>>>>>

>>>> Why do you think that disable low-level hardware not required which 

>>>> was

>>>> enabled before? Also for some platforms required to call

>>>> regulator_disable() which was enabled earlier in probe function.

>>>> So, I suggest to keep jump to error_init label.

>>> If I keep the jump to error_init label, then there is unbalanced 

>>> call to

>>> dwc2_lowlevel_hw_disable(). usb_add_gadget_udc() can fail in 2 places:

>>> on gadget->bind() or during udc_start(). In the first case, the HW was

>>> not yet enabled, so there is no need to disable it. In the latter one,

>>> the error might be returned only from the dwc2_lowlevel_hw_enable(), so

>>> again there is no need to call dwc2_lowlevel_hw_disable().

>>>

>>> If I keep the "goto error_init;" line, I get the following errors:

>>>

>>> dwc2 12480000.hsotg: dwc2_check_params: Invalid parameter besl=1

>>> dwc2 12480000.hsotg: dwc2_check_params: Invalid parameter

>>> g_np_tx_fifo_size=1024

>>> dwc2 12480000.hsotg: EPs: 16, dedicated fifos, 7808 entries in SPRAM

>>> Mass Storage Function, version: 2009/09/11

>>> LUN: removable file: (no medium)

>>> no file given for LUN0

>>> g_mass_storage 12480000.hsotg: failed to start g_mass_storage: -22

>>> ------------[ cut here ]------------

>>> WARNING: CPU: 3 PID: 49 at drivers/clk/clk.c:958

>>> clk_core_disable+0x1e4/0x314

>>> usb_device already disabled

>>> Modules linked in:

>>> CPU: 3 PID: 49 Comm: kworker/3:1 Not tainted

>>> 5.8.0-rc5-next-20200714-00003-g105f360ba595-dirty #8758

>>> Hardware name: Samsung Exynos (Flattened Device Tree)

>>> Workqueue: events deferred_probe_work_func

>>> [<c011184c>] (unwind_backtrace) from [<c010d250>] 

>>> (show_stack+0x10/0x14)

>>> [<c010d250>] (show_stack) from [<c051b8fc>] (dump_stack+0xbc/0xe8)

>>> [<c051b8fc>] (dump_stack) from [<c0126ed8>] (__warn+0xf0/0x108)

>>> [<c0126ed8>] (__warn) from [<c0126f64>] (warn_slowpath_fmt+0x74/0xb8)

>>> [<c0126f64>] (warn_slowpath_fmt) from [<c056c338>]

>>> (clk_core_disable+0x1e4/0x314)

>>> [<c056c338>] (clk_core_disable) from [<c056c480>]

>>> (clk_core_disable_lock+0x18/0x24)

>>> [<c056c480>] (clk_core_disable_lock) from [<c073f9d4>]

>>> (__dwc2_lowlevel_hw_disable+0x3c/0xa0)

>>> [<c073f9d4>] (__dwc2_lowlevel_hw_disable) from [<c0740188>]

>>> (dwc2_driver_probe+0x2d4/0x6ac)

>>> [<c0740188>] (dwc2_driver_probe) from [<c0653640>]

>>> (platform_drv_probe+0x6c/0xa4)

>>> [<c0653640>] (platform_drv_probe) from [<c0650bdc>]

>>> (really_probe+0x200/0x4fc)

>>> [<c0650bdc>] (really_probe) from [<c0651040>]

>>> (driver_probe_device+0x78/0x1fc)

>>> [<c0651040>] (driver_probe_device) from [<c064ea78>]

>>> (bus_for_each_drv+0x74/0xb8)

>>> [<c064ea78>] (bus_for_each_drv) from [<c065093c>]

>>> (__device_attach+0xd4/0x16c)

>>> [<c065093c>] (__device_attach) from [<c064fa3c>]

>>> (bus_probe_device+0x88/0x90)

>>> [<c064fa3c>] (bus_probe_device) from [<c064ff54>]

>>> (deferred_probe_work_func+0x3c/0xd0)

>>> [<c064ff54>] (deferred_probe_work_func) from [<c0148a5c>]

>>> (process_one_work+0x234/0x7dc)

>>> [<c0148a5c>] (process_one_work) from [<c0149048>] 

>>> (worker_thread+0x44/0x51c)

>>> [<c0149048>] (worker_thread) from [<c015039c>] (kthread+0x158/0x1a0)

>>> [<c015039c>] (kthread) from [<c0100114>] (ret_from_fork+0x14/0x20)

>>> Exception stack(0xee923fb0 to 0xee923ff8)

>>> ...

>>> irq event stamp: 36966

>>> hardirqs last  enabled at (36965): [<c02b92d8>] kfree+0x1a4/0x3f0

>>> hardirqs last disabled at (36966): [<c0569edc>] 

>>> clk_enable_lock+0x14/0x134

>>> softirqs last  enabled at (36814): [<c010174c>] 

>>> __do_softirq+0x50c/0x608

>>> softirqs last disabled at (36803): [<c0130218>] irq_exit+0x168/0x16c

>>> ---[ end trace f55f4b28f3080c12 ]---

>>> ------------[ cut here ]------------

>>> WARNING: CPU: 3 PID: 49 at drivers/clk/clk.c:817

>>> clk_core_unprepare+0x33c/0x470

>>> usb_device already unprepared

>>> Modules linked in:

>>> CPU: 3 PID: 49 Comm: kworker/3:1 Tainted: G        W

>>> 5.8.0-rc5-next-20200714-00003-g105f360ba595-dirty #8758

>>> Hardware name: Samsung Exynos (Flattened Device Tree)

>>> Workqueue: events deferred_probe_work_func

>>> [<c011184c>] (unwind_backtrace) from [<c010d250>] 

>>> (show_stack+0x10/0x14)

>>> [<c010d250>] (show_stack) from [<c051b8fc>] (dump_stack+0xbc/0xe8)

>>> [<c051b8fc>] (dump_stack) from [<c0126ed8>] (__warn+0xf0/0x108)

>>> [<c0126ed8>] (__warn) from [<c0126f64>] (warn_slowpath_fmt+0x74/0xb8)

>>> [<c0126f64>] (warn_slowpath_fmt) from [<c056dcb8>]

>>> (clk_core_unprepare+0x33c/0x470)

>>> [<c056dcb8>] (clk_core_unprepare) from [<c056de10>]

>>> (clk_unprepare+0x24/0x2c)

>>> [<c056de10>] (clk_unprepare) from [<c073f9dc>]

>>> (__dwc2_lowlevel_hw_disable+0x44/0xa0)

>>> [<c073f9dc>] (__dwc2_lowlevel_hw_disable) from [<c0740188>]

>>> (dwc2_driver_probe+0x2d4/0x6ac)

>>> [<c0740188>] (dwc2_driver_probe) from [<c0653640>]

>>> (platform_drv_probe+0x6c/0xa4)

>>> [<c0653640>] (platform_drv_probe) from [<c0650bdc>]

>>> (really_probe+0x200/0x4fc)

>>> [<c0650bdc>] (really_probe) from [<c0651040>]

>>> (driver_probe_device+0x78/0x1fc)

>>> [<c0651040>] (driver_probe_device) from [<c064ea78>]

>>> (bus_for_each_drv+0x74/0xb8)

>>> [<c064ea78>] (bus_for_each_drv) from [<c065093c>]

>>> (__device_attach+0xd4/0x16c)

>>> [<c065093c>] (__device_attach) from [<c064fa3c>]

>>> (bus_probe_device+0x88/0x90)

>>> [<c064fa3c>] (bus_probe_device) from [<c064ff54>]

>>> (deferred_probe_work_func+0x3c/0xd0)

>>> [<c064ff54>] (deferred_probe_work_func) from [<c0148a5c>]

>>> (process_one_work+0x234/0x7dc)

>>> [<c0148a5c>] (process_one_work) from [<c0149048>] 

>>> (worker_thread+0x44/0x51c)

>>> [<c0149048>] (worker_thread) from [<c015039c>] (kthread+0x158/0x1a0)

>>> [<c015039c>] (kthread) from [<c0100114>] (ret_from_fork+0x14/0x20)

>>> Exception stack(0xee923fb0 to 0xee923ff8)

>>> ...

>>> irq event stamp: 37073

>>> hardirqs last  enabled at (37081): [<c019d624>] 

>>> console_unlock+0x430/0x6cc

>>> hardirqs last disabled at (37108): [<c019d348>] 

>>> console_unlock+0x154/0x6cc

>>> softirqs last  enabled at (37124): [<c010174c>] 

>>> __do_softirq+0x50c/0x608

>>> softirqs last disabled at (37135): [<c0130218>] irq_exit+0x168/0x16c

>>> ---[ end trace f55f4b28f3080c13 ]---

>>> ------------[ cut here ]------------

>>> WARNING: CPU: 3 PID: 49 at drivers/regulator/core.c:2603

>>> _regulator_disable+0x180/0x1d8

>>> unbalanced disables for VUOTG_3.0V

>>> Modules linked in:

>>> CPU: 3 PID: 49 Comm: kworker/3:1 Tainted: G        W

>>> 5.8.0-rc5-next-20200714-00003-g105f360ba595-dirty #8758

>>> Hardware name: Samsung Exynos (Flattened Device Tree)

>>> Workqueue: events deferred_probe_work_func

>>> [<c011184c>] (unwind_backtrace) from [<c010d250>] 

>>> (show_stack+0x10/0x14)

>>> [<c010d250>] (show_stack) from [<c051b8fc>] (dump_stack+0xbc/0xe8)

>>> [<c051b8fc>] (dump_stack) from [<c0126ed8>] (__warn+0xf0/0x108)

>>> [<c0126ed8>] (__warn) from [<c0126f64>] (warn_slowpath_fmt+0x74/0xb8)

>>> [<c0126f64>] (warn_slowpath_fmt) from [<c0585e78>]

>>> (_regulator_disable+0x180/0x1d8)

>>> [<c0585e78>] (_regulator_disable) from [<c0585f04>]

>>> (regulator_disable+0x34/0xe0)

>>> [<c0585f04>] (regulator_disable) from [<c0587ef8>]

>>> (regulator_bulk_disable+0x28/0xb0)

>>> [<c0587ef8>] (regulator_bulk_disable) from [<c0740188>]

>>> (dwc2_driver_probe+0x2d4/0x6ac)

>>> [<c0740188>] (dwc2_driver_probe) from [<c0653640>]

>>> (platform_drv_probe+0x6c/0xa4)

>>> [<c0653640>] (platform_drv_probe) from [<c0650bdc>]

>>> (really_probe+0x200/0x4fc)

>>> [<c0650bdc>] (really_probe) from [<c0651040>]

>>> (driver_probe_device+0x78/0x1fc)

>>> [<c0651040>] (driver_probe_device) from [<c064ea78>]

>>> (bus_for_each_drv+0x74/0xb8)

>>> [<c064ea78>] (bus_for_each_drv) from [<c065093c>]

>>> (__device_attach+0xd4/0x16c)

>>> [<c065093c>] (__device_attach) from [<c064fa3c>]

>>> (bus_probe_device+0x88/0x90)

>>> [<c064fa3c>] (bus_probe_device) from [<c064ff54>]

>>> (deferred_probe_work_func+0x3c/0xd0)

>>> [<c064ff54>] (deferred_probe_work_func) from [<c0148a5c>]

>>> (process_one_work+0x234/0x7dc)

>>> [<c0148a5c>] (process_one_work) from [<c0149048>] 

>>> (worker_thread+0x44/0x51c)

>>> [<c0149048>] (worker_thread) from [<c015039c>] (kthread+0x158/0x1a0)

>>> [<c015039c>] (kthread) from [<c0100114>] (ret_from_fork+0x14/0x20)

>>> Exception stack(0xee923fb0 to 0xee923ff8)

>>> ...

>>> irq event stamp: 37243

>>> hardirqs last  enabled at (37251): [<c019d624>] 

>>> console_unlock+0x430/0x6cc

>>> hardirqs last disabled at (37274): [<c0ac0790>] __schedule+0xd8/0x860

>>> softirqs last  enabled at (37270): [<c010174c>] 

>>> __do_softirq+0x50c/0x608

>>> softirqs last disabled at (37291): [<c0130218>] irq_exit+0x168/0x16c

>>> ---[ end trace f55f4b28f3080c14 ]---

>>> Failed to disable vusb_a: -5

>>> dwc2: probe of 12480000.hsotg failed with error -22

>>> 8<--- cut here ---

>>> Unable to handle kernel NULL pointer dereference at virtual address 

>>> 00000004

>>> pgd = (ptrval)

>>> [00000004] *pgd=00000000

>>> Internal error: Oops: 5 [#1] PREEMPT SMP ARM

>>> Modules linked in:

>>> CPU: 3 PID: 87 Comm: kworker/3:2 Tainted: G        W

>>> 5.8.0-rc5-next-20200714-00003-g105f360ba595-dirty #8758

>>> Hardware name: Samsung Exynos (Flattened Device Tree)

>>> Workqueue:  0x0 (rcu_gp)

>>> PC is at process_one_work+0x44/0x7dc

>>> LR is at 0xedc226d0

>>> ...

>>> Process kworker/3:2 (pid: 87, stack limit = 0x(ptrval))

>>> Stack: (0xeda03f00 to 0xeda04000)

>>> ...

>>> [<c014886c>] (process_one_work) from [<c0149048>] 

>>> (worker_thread+0x44/0x51c)

>>> [<c0149048>] (worker_thread) from [<c015039c>] (kthread+0x158/0x1a0)

>>> [<c015039c>] (kthread) from [<c0100114>] (ret_from_fork+0x14/0x20)

>>> Exception stack(0xeda03fb0 to 0xeda03ff8)

>>> ...

>>> ---[ end trace f55f4b28f3080c15 ]---

>>> note: kworker/3:2[87] exited with preempt_count 1

>>>

>>> Best regards

>>>

>> I guess you build driver in (hsotg->dr_mode == USB_DR_MODE_PERIPHERAL)

>> and this is why call of dwc2_lowlevel_hw_disable() at 'error:' label

>> create issue. Could you please test on your setup follow implementation:

>> ...

>> error:

>>     if (hsotg->dr_mode != USB_DR_MODE_PERIPHERAL)

>>         dwc2_lowlevel_hw_disable(hsotg);

>>     return retval;

>> }

>> ...

>

> Right, this will work. However, I would also change the order of 

> operations - disabling usb33d regulator should be done after disabling 

> lowlevel hardware to properly pair with the enable operations.

>

My fault, I've mixed vbus and usb33d regulators. The order is correct.

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland
diff mbox series

Patch

diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index c347d93eae64..a6022dc4766d 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -581,8 +581,9 @@  static int dwc2_driver_probe(struct platform_device *dev)
 	if (hsotg->gadget_enabled) {
 		retval = usb_add_gadget_udc(hsotg->dev, &hsotg->gadget);
 		if (retval) {
+			hsotg->gadget.udc = NULL;
 			dwc2_hsotg_remove(hsotg);
-			goto error_init;
+			return retval;
 		}
 	}
 #endif /* CONFIG_USB_DWC2_PERIPHERAL || CONFIG_USB_DWC2_DUAL_ROLE */