diff options
| author | Shawn Guo <shawn.guo@linaro.org> | 2022-10-12 20:13:53 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-11-03 04:12:09 +0100 |
| commit | 4561d8008a467cb05ac632a215391d6b787f40aa (patch) | |
| tree | 55182840e6d0eadb30c1b7475845f5565afa1210 /drivers/tty | |
| parent | 76bad3f88750f8cc465c489e6846249e0bc3d8f5 (diff) | |
serial: imx: Add missing .thaw_noirq hook
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()
Fixes: 09df0b3464e5 ("serial: imx: fix endless loop during suspend")
Reviewed-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Link: https://lore.kernel.org/r/20221012121353.2346280-1-shawn.guo@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/imx.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 05b432dc7a85..aadda66405b4 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -2594,6 +2594,7 @@ 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, |