Re: [PATCH] Input: cyapa - add missing input core locking to suspend/resume functions

[Marek Szyprowski <m.szyprowski@samsung.com>]

On 09.10.2023 14:10, Marek Szyprowski wrote:
> Grab input->mutex during suspend/resume functions like it is done in
> other input drivers. This fixes the following warning during system
> suspend/resume cycle on Samsung Exynos5250-based Snow Chromebook:
>
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 1680 at drivers/input/input.c:2291 input_device_enabled+0x68/0x6c
> Modules linked in: ...
> CPU: 1 PID: 1680 Comm: kworker/u4:12 Tainted: G        W          6.6.0-rc5-next-20231009 #14109
> Hardware name: Samsung Exynos (Flattened Device Tree)
> Workqueue: events_unbound async_run_entry_fn
>   unwind_backtrace from show_stack+0x10/0x14
>   show_stack from dump_stack_lvl+0x58/0x70
>   dump_stack_lvl from __warn+0x1a8/0x1cc
>   __warn from warn_slowpath_fmt+0x18c/0x1b4
>   warn_slowpath_fmt from input_device_enabled+0x68/0x6c
>   input_device_enabled from cyapa_gen3_set_power_mode+0x13c/0x1dc
>   cyapa_gen3_set_power_mode from cyapa_reinitialize+0x10c/0x15c
>   cyapa_reinitialize from cyapa_resume+0x48/0x98
>   cyapa_resume from dpm_run_callback+0x90/0x298
>   dpm_run_callback from device_resume+0xb4/0x258
>   device_resume from async_resume+0x20/0x64
>   async_resume from async_run_entry_fn+0x40/0x15c
>   async_run_entry_fn from process_scheduled_works+0xbc/0x6a8
>   process_scheduled_works from worker_thread+0x188/0x454
>   worker_thread from kthread+0x108/0x140
>   kthread from ret_from_fork+0x14/0x28
> Exception stack(0xf1625fb0 to 0xf1625ff8)
> ...
> ---[ end trace 0000000000000000 ]---
> ...
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 1680 at drivers/input/input.c:2291 input_device_enabled+0x68/0x6c
> Modules linked in: ...
> CPU: 1 PID: 1680 Comm: kworker/u4:12 Tainted: G        W          6.6.0-rc5-next-20231009 #14109
> Hardware name: Samsung Exynos (Flattened Device Tree)
> Workqueue: events_unbound async_run_entry_fn
>   unwind_backtrace from show_stack+0x10/0x14
>   show_stack from dump_stack_lvl+0x58/0x70
>   dump_stack_lvl from __warn+0x1a8/0x1cc
>   __warn from warn_slowpath_fmt+0x18c/0x1b4
>   warn_slowpath_fmt from input_device_enabled+0x68/0x6c
>   input_device_enabled from cyapa_gen3_set_power_mode+0x13c/0x1dc
>   cyapa_gen3_set_power_mode from cyapa_reinitialize+0x10c/0x15c
>   cyapa_reinitialize from cyapa_resume+0x48/0x98
>   cyapa_resume from dpm_run_callback+0x90/0x298
>   dpm_run_callback from device_resume+0xb4/0x258
>   device_resume from async_resume+0x20/0x64
>   async_resume from async_run_entry_fn+0x40/0x15c
>   async_run_entry_fn from process_scheduled_works+0xbc/0x6a8
>   process_scheduled_works from worker_thread+0x188/0x454
>   worker_thread from kthread+0x108/0x140
>   kthread from ret_from_fork+0x14/0x28
> Exception stack(0xf1625fb0 to 0xf1625ff8)
> ...
> ---[ end trace 0000000000000000 ]---
>
> Fixes: d69f0a43c677 ("Input: use input_device_enabled()")
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

Gentle ping?

> ---
>   drivers/input/mouse/cyapa.c | 12 +++++++++++-
>   1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/input/mouse/cyapa.c b/drivers/input/mouse/cyapa.c
> index a84098448f5b..cf23f95b5f11 100644
> --- a/drivers/input/mouse/cyapa.c
> +++ b/drivers/input/mouse/cyapa.c
> @@ -1347,10 +1347,16 @@ static int cyapa_suspend(struct device *dev)
>   	u8 power_mode;
>   	int error;
>   
> -	error = mutex_lock_interruptible(&cyapa->state_sync_lock);
> +	error = mutex_lock_interruptible(&cyapa->input->mutex);
>   	if (error)
>   		return error;
>   
> +	error = mutex_lock_interruptible(&cyapa->state_sync_lock);
> +	if (error) {
> +		mutex_unlock(&cyapa->input->mutex);
> +		return error;
> +	}
> +
>   	/*
>   	 * Runtime PM is enable only when device is in operational mode and
>   	 * users in use, so need check it before disable it to
> @@ -1385,6 +1391,8 @@ static int cyapa_suspend(struct device *dev)
>   		cyapa->irq_wake = (enable_irq_wake(client->irq) == 0);
>   
>   	mutex_unlock(&cyapa->state_sync_lock);
> +	mutex_unlock(&cyapa->input->mutex);
> +
>   	return 0;
>   }
>   
> @@ -1394,6 +1402,7 @@ static int cyapa_resume(struct device *dev)
>   	struct cyapa *cyapa = i2c_get_clientdata(client);
>   	int error;
>   
> +	mutex_lock(&cyapa->input->mutex);
>   	mutex_lock(&cyapa->state_sync_lock);
>   
>   	if (device_may_wakeup(dev) && cyapa->irq_wake) {
> @@ -1412,6 +1421,7 @@ static int cyapa_resume(struct device *dev)
>   	enable_irq(client->irq);
>   
>   	mutex_unlock(&cyapa->state_sync_lock);
> +	mutex_unlock(&cyapa->input->mutex);
>   	return 0;
>   }
>   

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