2021-04-07 17:50:55

by Dinghao Liu

Subject: [PATCH] Input: cyapa - Fix rumtime PM imbalance on error

When mutex_lock_interruptible() fails, a pairing PM usage
counter decrement is needed to keep the counter balanced.

Signed-off-by: Dinghao Liu <[email protected]>
---
drivers/input/mouse/cyapa.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/input/mouse/cyapa.c b/drivers/input/mouse/cyapa.c
index 77cc653edca2..e411ab45a218 100644
--- a/drivers/input/mouse/cyapa.c
+++ b/drivers/input/mouse/cyapa.c
@@ -904,8 +904,10 @@ static ssize_t cyapa_update_rt_suspend_scanrate(struct device *dev,
pm_runtime_get_sync(dev);

error = mutex_lock_interruptible(&cyapa->state_sync_lock);
- if (error)
+ if (error) {
+ pm_runtime_put_noidle(dev);
return error;
+ }

cyapa->runtime_suspend_sleep_time = min_t(u16, time, 1000);
cyapa->runtime_suspend_power_mode =
--
2.17.1

2021-04-08 06:23:15

by Dmitry Torokhov

Subject: Re: [PATCH] Input: cyapa - Fix rumtime PM imbalance on error

Hi Dinghao,

On Wed, Apr 07, 2021 at 12:07:38PM +0800, Dinghao Liu wrote:
> When mutex_lock_interruptible() fails, a pairing PM usage
> counter decrement is needed to keep the counter balanced.

Thank you for the patch.

>
> Signed-off-by: Dinghao Liu <[email protected]>
> ---
> drivers/input/mouse/cyapa.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/input/mouse/cyapa.c b/drivers/input/mouse/cyapa.c
> index 77cc653edca2..e411ab45a218 100644
> --- a/drivers/input/mouse/cyapa.c
> +++ b/drivers/input/mouse/cyapa.c
> @@ -904,8 +904,10 @@ static ssize_t cyapa_update_rt_suspend_scanrate(struct device *dev,
> pm_runtime_get_sync(dev);
>
> error = mutex_lock_interruptible(&cyapa->state_sync_lock);
> - if (error)
> + if (error) {
> + pm_runtime_put_noidle(dev);

Why "noidle" and not pm_runtime_put_sync_autosuspend() like we do in
case of normal flow?

> return error;
> + }
>
> cyapa->runtime_suspend_sleep_time = min_t(u16, time, 1000);
> cyapa->runtime_suspend_power_mode =
> --
> 2.17.1
>

Thanks.

--
Dmitry

2021-04-08 06:33:17

by Dinghao Liu

Subject: Re: Re: [PATCH] Input: cyapa - Fix rumtime PM imbalance on error

> Hi Dinghao,
>
> On Wed, Apr 07, 2021 at 12:07:38PM +0800, Dinghao Liu wrote:
> > When mutex_lock_interruptible() fails, a pairing PM usage
> > counter decrement is needed to keep the counter balanced.
>
> Thank you for the patch.
>
> >
> > Signed-off-by: Dinghao Liu <[email protected]>
> > ---
> > drivers/input/mouse/cyapa.c | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/input/mouse/cyapa.c b/drivers/input/mouse/cyapa.c
> > index 77cc653edca2..e411ab45a218 100644
> > --- a/drivers/input/mouse/cyapa.c
> > +++ b/drivers/input/mouse/cyapa.c
> > @@ -904,8 +904,10 @@ static ssize_t cyapa_update_rt_suspend_scanrate(struct device *dev,
> > pm_runtime_get_sync(dev);
> >
> > error = mutex_lock_interruptible(&cyapa->state_sync_lock);
> > - if (error)
> > + if (error) {
> > + pm_runtime_put_noidle(dev);
>
> Why "noidle" and not pm_runtime_put_sync_autosuspend() like we do in
> case of normal flow?
>

pm_runtime_put_noidle() only decrease the refcount, while
pm_runtime_put_sync_autosuspend() will execute an extra
pm_runtime_autosuspend(). I'm not sure if the autosuspend is necessary
in this error handling path, so I only balance the counter.

Regards,
Dinghao