| Message ID | 20221012121353.2346280-1-shawn.guo@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | serial: imx: Add missing .thaw_noirq hook | expand |
Thus wrote Shawn Guo (shawn.guo@linaro.org): > The following warning is seen with non-console UART instance when > system hibernates. > [ 37.371969] ------------[ cut here ]------------ > [ 37.376599] uart3_root_clk already disabled > [ 37.380810] WARNING: CPU: 0 PID: 296 at drivers/clk/clk.c:952 clk_core_disable+0xa4/0xb0 > ... > [ 37.506986] Call trace: > [ 37.509432] clk_core_disable+0xa4/0xb0 > [ 37.513270] clk_disable+0x34/0x50 > [ 37.516672] imx_uart_thaw+0x38/0x5c > [ 37.520250] platform_pm_thaw+0x30/0x6c > [ 37.524089] dpm_run_callback.constprop.0+0x3c/0xd4 > [ 37.528972] device_resume+0x7c/0x160 > [ 37.532633] dpm_resume+0xe8/0x230 > [ 37.536036] hibernation_snapshot+0x288/0x430 > [ 37.540397] hibernate+0x10c/0x2e0 > [ 37.543798] state_store+0xc4/0xd0 > [ 37.547203] kobj_attr_store+0x1c/0x30 > [ 37.550953] sysfs_kf_write+0x48/0x60 > [ 37.554619] kernfs_fop_write_iter+0x118/0x1ac > [ 37.559063] new_sync_write+0xe8/0x184 > [ 37.562812] vfs_write+0x230/0x290 > [ 37.566214] ksys_write+0x68/0xf4 > [ 37.569529] __arm64_sys_write+0x20/0x2c > [ 37.573452] invoke_syscall.constprop.0+0x50/0xf0 > [ 37.578156] do_el0_svc+0x11c/0x150 > [ 37.581648] el0_svc+0x30/0x140 > [ 37.584792] el0t_64_sync_handler+0xe8/0xf0 > [ 37.588976] el0t_64_sync+0x1a0/0x1a4 > [ 37.592639] ---[ end trace 56e22eec54676d75 ]--- > On hibernating, pm core calls into related hooks in sequence like: > .freeze > .freeze_noirq > .thaw_noirq > .thaw > With .thaw_noirq hook being absent, the clock will be disabled in a > unbalanced call which results the warning above. > imx_uart_freeze() > clk_prepare_enable() > imx_uart_suspend_noirq() > clk_disable() > imx_uart_thaw > clk_disable_unprepare() > Adding the missing .thaw_noirq hook as imx_uart_resume_noirq() will have > the call sequence corrected as below and thus fix the warning. > imx_uart_freeze() > clk_prepare_enable() > imx_uart_suspend_noirq() > clk_disable() > imx_uart_resume_noirq() > clk_enable() > imx_uart_thaw > clk_disable_unprepare() > Signed-off-by: Shawn Guo <shawn.guo@linaro.org> > --- > drivers/tty/serial/imx.c | 1 + > 1 file changed, 1 insertion(+) > diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c > index 590a25369531..e5163c2c4169 100644 > --- a/drivers/tty/serial/imx.c > +++ b/drivers/tty/serial/imx.c > @@ -2603,6 +2603,7 @@ static const struct dev_pm_ops imx_uart_pm_ops = { > .suspend_noirq = imx_uart_suspend_noirq, > .resume_noirq = imx_uart_resume_noirq, > .freeze_noirq = imx_uart_suspend_noirq, > + .thaw_noirq = imx_uart_resume_noirq, > .restore_noirq = imx_uart_resume_noirq, > .suspend = imx_uart_suspend, > .resume = imx_uart_resume, > -- > 2.25.1 Reviewed-by: Martin Kaiser <martin@kaiser.cx> Thanks, Martin
On Wed, Oct 12, 2022 at 08:13:53PM +0800, Shawn Guo wrote: > The following warning is seen with non-console UART instance when > system hibernates. > > [ 37.371969] ------------[ cut here ]------------ > [ 37.376599] uart3_root_clk already disabled > [ 37.380810] WARNING: CPU: 0 PID: 296 at drivers/clk/clk.c:952 clk_core_disable+0xa4/0xb0 > ... > [ 37.506986] Call trace: > [ 37.509432] clk_core_disable+0xa4/0xb0 > [ 37.513270] clk_disable+0x34/0x50 > [ 37.516672] imx_uart_thaw+0x38/0x5c > [ 37.520250] platform_pm_thaw+0x30/0x6c > [ 37.524089] dpm_run_callback.constprop.0+0x3c/0xd4 > [ 37.528972] device_resume+0x7c/0x160 > [ 37.532633] dpm_resume+0xe8/0x230 > [ 37.536036] hibernation_snapshot+0x288/0x430 > [ 37.540397] hibernate+0x10c/0x2e0 > [ 37.543798] state_store+0xc4/0xd0 > [ 37.547203] kobj_attr_store+0x1c/0x30 > [ 37.550953] sysfs_kf_write+0x48/0x60 > [ 37.554619] kernfs_fop_write_iter+0x118/0x1ac > [ 37.559063] new_sync_write+0xe8/0x184 > [ 37.562812] vfs_write+0x230/0x290 > [ 37.566214] ksys_write+0x68/0xf4 > [ 37.569529] __arm64_sys_write+0x20/0x2c > [ 37.573452] invoke_syscall.constprop.0+0x50/0xf0 > [ 37.578156] do_el0_svc+0x11c/0x150 > [ 37.581648] el0_svc+0x30/0x140 > [ 37.584792] el0t_64_sync_handler+0xe8/0xf0 > [ 37.588976] el0t_64_sync+0x1a0/0x1a4 > [ 37.592639] ---[ end trace 56e22eec54676d75 ]--- > > On hibernating, pm core calls into related hooks in sequence like: > > .freeze > .freeze_noirq > .thaw_noirq > .thaw > > With .thaw_noirq hook being absent, the clock will be disabled in a > unbalanced call which results the warning above. > > imx_uart_freeze() > clk_prepare_enable() > imx_uart_suspend_noirq() > clk_disable() > imx_uart_thaw > clk_disable_unprepare() > > Adding the missing .thaw_noirq hook as imx_uart_resume_noirq() will have > the call sequence corrected as below and thus fix the warning. > > imx_uart_freeze() > clk_prepare_enable() > imx_uart_suspend_noirq() > clk_disable() > imx_uart_resume_noirq() > clk_enable() > imx_uart_thaw > clk_disable_unprepare() > > Signed-off-by: Shawn Guo <shawn.guo@linaro.org> What commit id does this fix, and does it need to go to older/stable kernels? thanks, greg k-h
On Wed, Oct 12, 2022 at 06:20:35PM +0200, Greg Kroah-Hartman wrote: > On Wed, Oct 12, 2022 at 08:13:53PM +0800, Shawn Guo wrote: > > The following warning is seen with non-console UART instance when > > system hibernates. > > > > [ 37.371969] ------------[ cut here ]------------ > > [ 37.376599] uart3_root_clk already disabled > > [ 37.380810] WARNING: CPU: 0 PID: 296 at drivers/clk/clk.c:952 clk_core_disable+0xa4/0xb0 > > ... > > [ 37.506986] Call trace: > > [ 37.509432] clk_core_disable+0xa4/0xb0 > > [ 37.513270] clk_disable+0x34/0x50 > > [ 37.516672] imx_uart_thaw+0x38/0x5c > > [ 37.520250] platform_pm_thaw+0x30/0x6c > > [ 37.524089] dpm_run_callback.constprop.0+0x3c/0xd4 > > [ 37.528972] device_resume+0x7c/0x160 > > [ 37.532633] dpm_resume+0xe8/0x230 > > [ 37.536036] hibernation_snapshot+0x288/0x430 > > [ 37.540397] hibernate+0x10c/0x2e0 > > [ 37.543798] state_store+0xc4/0xd0 > > [ 37.547203] kobj_attr_store+0x1c/0x30 > > [ 37.550953] sysfs_kf_write+0x48/0x60 > > [ 37.554619] kernfs_fop_write_iter+0x118/0x1ac > > [ 37.559063] new_sync_write+0xe8/0x184 > > [ 37.562812] vfs_write+0x230/0x290 > > [ 37.566214] ksys_write+0x68/0xf4 > > [ 37.569529] __arm64_sys_write+0x20/0x2c > > [ 37.573452] invoke_syscall.constprop.0+0x50/0xf0 > > [ 37.578156] do_el0_svc+0x11c/0x150 > > [ 37.581648] el0_svc+0x30/0x140 > > [ 37.584792] el0t_64_sync_handler+0xe8/0xf0 > > [ 37.588976] el0t_64_sync+0x1a0/0x1a4 > > [ 37.592639] ---[ end trace 56e22eec54676d75 ]--- > > > > On hibernating, pm core calls into related hooks in sequence like: > > > > .freeze > > .freeze_noirq > > .thaw_noirq > > .thaw > > > > With .thaw_noirq hook being absent, the clock will be disabled in a > > unbalanced call which results the warning above. > > > > imx_uart_freeze() > > clk_prepare_enable() > > imx_uart_suspend_noirq() > > clk_disable() > > imx_uart_thaw > > clk_disable_unprepare() > > > > Adding the missing .thaw_noirq hook as imx_uart_resume_noirq() will have > > the call sequence corrected as below and thus fix the warning. > > > > imx_uart_freeze() > > clk_prepare_enable() > > imx_uart_suspend_noirq() > > clk_disable() > > imx_uart_resume_noirq() > > clk_enable() > > imx_uart_thaw > > clk_disable_unprepare() > > > > Signed-off-by: Shawn Guo <shawn.guo@linaro.org> > > What commit id does this fix, and does it need to go to older/stable > kernels? The .thaw_noirq was missing from commit 94be6d74d040 ("serial: imx: add hibernation support"), but it did not cause the warning until commit 09df0b3464e5 ("serial: imx: fix endless loop during suspend") changes clock calls. So I should have added: Fixes: 09df0b3464e5 ("serial: imx: fix endless loop during suspend") Shawn
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 590a25369531..e5163c2c4169 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -2603,6 +2603,7 @@ static const struct dev_pm_ops imx_uart_pm_ops = { .suspend_noirq = imx_uart_suspend_noirq, .resume_noirq = imx_uart_resume_noirq, .freeze_noirq = imx_uart_suspend_noirq, + .thaw_noirq = imx_uart_resume_noirq, .restore_noirq = imx_uart_resume_noirq, .suspend = imx_uart_suspend, .resume = imx_uart_resume,
The following warning is seen with non-console UART instance when system hibernates. [ 37.371969] ------------[ cut here ]------------ [ 37.376599] uart3_root_clk already disabled [ 37.380810] WARNING: CPU: 0 PID: 296 at drivers/clk/clk.c:952 clk_core_disable+0xa4/0xb0 ... [ 37.506986] Call trace: [ 37.509432] clk_core_disable+0xa4/0xb0 [ 37.513270] clk_disable+0x34/0x50 [ 37.516672] imx_uart_thaw+0x38/0x5c [ 37.520250] platform_pm_thaw+0x30/0x6c [ 37.524089] dpm_run_callback.constprop.0+0x3c/0xd4 [ 37.528972] device_resume+0x7c/0x160 [ 37.532633] dpm_resume+0xe8/0x230 [ 37.536036] hibernation_snapshot+0x288/0x430 [ 37.540397] hibernate+0x10c/0x2e0 [ 37.543798] state_store+0xc4/0xd0 [ 37.547203] kobj_attr_store+0x1c/0x30 [ 37.550953] sysfs_kf_write+0x48/0x60 [ 37.554619] kernfs_fop_write_iter+0x118/0x1ac [ 37.559063] new_sync_write+0xe8/0x184 [ 37.562812] vfs_write+0x230/0x290 [ 37.566214] ksys_write+0x68/0xf4 [ 37.569529] __arm64_sys_write+0x20/0x2c [ 37.573452] invoke_syscall.constprop.0+0x50/0xf0 [ 37.578156] do_el0_svc+0x11c/0x150 [ 37.581648] el0_svc+0x30/0x140 [ 37.584792] el0t_64_sync_handler+0xe8/0xf0 [ 37.588976] el0t_64_sync+0x1a0/0x1a4 [ 37.592639] ---[ end trace 56e22eec54676d75 ]--- On hibernating, pm core calls into related hooks in sequence like: .freeze .freeze_noirq .thaw_noirq .thaw With .thaw_noirq hook being absent, the clock will be disabled in a unbalanced call which results the warning above. imx_uart_freeze() clk_prepare_enable() imx_uart_suspend_noirq() clk_disable() imx_uart_thaw clk_disable_unprepare() Adding the missing .thaw_noirq hook as imx_uart_resume_noirq() will have the call sequence corrected as below and thus fix the warning. imx_uart_freeze() clk_prepare_enable() imx_uart_suspend_noirq() clk_disable() imx_uart_resume_noirq() clk_enable() imx_uart_thaw clk_disable_unprepare() Signed-off-by: Shawn Guo <shawn.guo@linaro.org> --- drivers/tty/serial/imx.c | 1 + 1 file changed, 1 insertion(+)