[PATCH] Input: synaptics-rmi4 - add missed operations in remove

[PATCH] Input: synaptics-rmi4 - add missed operations in remove

[Chuhong Yuan]

The driver forgets to deal with work and workqueue in remove like what
is done when probe fails.
Add the missed operations to fix it.

Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
---
 drivers/input/rmi4/rmi_f54.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/input/rmi4/rmi_f54.c b/drivers/input/rmi4/rmi_f54.c
index 710b02595486..2c0cde5c775c 100644
--- a/drivers/input/rmi4/rmi_f54.c
+++ b/drivers/input/rmi4/rmi_f54.c
@@ -730,6 +730,9 @@ static void rmi_f54_remove(struct rmi_function *fn)
 
 	video_unregister_device(&f54->vdev);
 	v4l2_device_unregister(&f54->v4l2);
+	cancel_delayed_work_sync(&f54->work);
+	flush_workqueue(f54->workqueue);
+	destroy_workqueue(f54->workqueue);
 }
 
 struct rmi_function_handler rmi_f54_handler = {
-- 
2.23.0

Re: [PATCH] Input: synaptics-rmi4 - add missed operations in remove

[Dmitry Torokhov]

On Wed, Nov 13, 2019 at 02:36:56PM +0800, Chuhong Yuan wrote:
> The driver forgets to deal with work and workqueue in remove like what
> is done when probe fails.
> Add the missed operations to fix it.

Is it really possible for the work to still be pending when fully
registered device is properly unregistered? I thought we'd wait for
successful data acquisition in rmi_f54_buffer_queue() before unregister
can complete.

> 
> Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
> ---
>  drivers/input/rmi4/rmi_f54.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/input/rmi4/rmi_f54.c b/drivers/input/rmi4/rmi_f54.c
> index 710b02595486..2c0cde5c775c 100644
> --- a/drivers/input/rmi4/rmi_f54.c
> +++ b/drivers/input/rmi4/rmi_f54.c
> @@ -730,6 +730,9 @@ static void rmi_f54_remove(struct rmi_function *fn)
>  
>  	video_unregister_device(&f54->vdev);
>  	v4l2_device_unregister(&f54->v4l2);
> +	cancel_delayed_work_sync(&f54->work);
> +	flush_workqueue(f54->workqueue);
> +	destroy_workqueue(f54->workqueue);
>  }
>  
>  struct rmi_function_handler rmi_f54_handler = {
> -- 
> 2.23.0
> 

Thanks.

-- 
Dmitry

Re: [PATCH] Input: synaptics-rmi4 - add missed operations in remove

[Chuhong Yuan]

On Wed, Nov 13, 2019 at 4:23 PM Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:
>
> On Wed, Nov 13, 2019 at 02:36:56PM +0800, Chuhong Yuan wrote:
> > The driver forgets to deal with work and workqueue in remove like what
> > is done when probe fails.
> > Add the missed operations to fix it.
>
> Is it really possible for the work to still be pending when fully
> registered device is properly unregistered? I thought we'd wait for
> successful data acquisition in rmi_f54_buffer_queue() before unregister
> can complete.
>

In fact, I am not familiar with the mechanism here...
I have checked other drivers with video_unregister_device and found none of
them deals with work in remove.
Therefore, I think your opinion should be right and we only need to deal with
the workqueue.

Regards,
Chuhong

> >
> > Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
> > ---
> >  drivers/input/rmi4/rmi_f54.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/input/rmi4/rmi_f54.c b/drivers/input/rmi4/rmi_f54.c
> > index 710b02595486..2c0cde5c775c 100644
> > --- a/drivers/input/rmi4/rmi_f54.c
> > +++ b/drivers/input/rmi4/rmi_f54.c
> > @@ -730,6 +730,9 @@ static void rmi_f54_remove(struct rmi_function *fn)
> >
> >       video_unregister_device(&f54->vdev);
> >       v4l2_device_unregister(&f54->v4l2);
> > +     cancel_delayed_work_sync(&f54->work);
> > +     flush_workqueue(f54->workqueue);
> > +     destroy_workqueue(f54->workqueue);
> >  }
> >
> >  struct rmi_function_handler rmi_f54_handler = {
> > --
> > 2.23.0
> >
>
> Thanks.
>
> --
> Dmitry

Re: [PATCH] Input: synaptics-rmi4 - add missed operations in remove

[Dmitry Torokhov]

On Wed, Nov 13, 2019 at 04:52:59PM +0800, Chuhong Yuan wrote:
> On Wed, Nov 13, 2019 at 4:23 PM Dmitry Torokhov
> <dmitry.torokhov@gmail.com> wrote:
> >
> > On Wed, Nov 13, 2019 at 02:36:56PM +0800, Chuhong Yuan wrote:
> > > The driver forgets to deal with work and workqueue in remove like what
> > > is done when probe fails.
> > > Add the missed operations to fix it.
> >
> > Is it really possible for the work to still be pending when fully
> > registered device is properly unregistered? I thought we'd wait for
> > successful data acquisition in rmi_f54_buffer_queue() before unregister
> > can complete.
> >
> 
> In fact, I am not familiar with the mechanism here...
> I have checked other drivers with video_unregister_device and found none of
> them deals with work in remove.
> Therefore, I think your opinion should be right and we only need to deal with
> the workqueue.

OK, please send the updated patch then.

Thanks!

-- 
Dmitry