diff mbox series

[2/3] media: i2c: imx219: Serialize during stream start/stop

Message ID 20210310122014.28353-3-prabhakar.mahadev-lad.rj@bp.renesas.com (mailing list archive)
State Superseded
Delegated to: Kieran Bingham
Headers show
Series media: i2c: imx219: Trivial Fixes | expand

Commit Message

Lad Prabhakar March 10, 2021, 12:20 p.m. UTC
Serialize during stream start/stop in suspend/resume callbacks.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
 drivers/media/i2c/imx219.c | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Laurent Pinchart March 10, 2021, 12:39 p.m. UTC | #1
Hi Prabhakar,

Thank you for the patch.

On Wed, Mar 10, 2021 at 12:20:13PM +0000, Lad Prabhakar wrote:
> Serialize during stream start/stop in suspend/resume callbacks.

Could you please explain why this is needed ?

> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> ---
>  drivers/media/i2c/imx219.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/media/i2c/imx219.c b/drivers/media/i2c/imx219.c
> index f0cf1985a4dc..87c021de1460 100644
> --- a/drivers/media/i2c/imx219.c
> +++ b/drivers/media/i2c/imx219.c
> @@ -1172,8 +1172,10 @@ static int __maybe_unused imx219_suspend(struct device *dev)
>  	struct v4l2_subdev *sd = dev_get_drvdata(dev);
>  	struct imx219 *imx219 = to_imx219(sd);
>  
> +	mutex_lock(&imx219->mutex);
>  	if (imx219->streaming)
>  		imx219_stop_streaming(imx219);
> +	mutex_unlock(&imx219->mutex);
>  
>  	return 0;
>  }
> @@ -1184,11 +1186,13 @@ static int __maybe_unused imx219_resume(struct device *dev)
>  	struct imx219 *imx219 = to_imx219(sd);
>  	int ret;
>  
> +	mutex_lock(&imx219->mutex);
>  	if (imx219->streaming) {
>  		ret = imx219_start_streaming(imx219);
>  		if (ret)
>  			goto error;
>  	}
> +	mutex_unlock(&imx219->mutex);
>  
>  	return 0;
>  
> @@ -1197,6 +1201,7 @@ static int __maybe_unused imx219_resume(struct device *dev)
>  	imx219->streaming = false;
>  	__v4l2_ctrl_grab(imx219->vflip, false);
>  	__v4l2_ctrl_grab(imx219->hflip, false);
> +	mutex_unlock(&imx219->mutex);
>  
>  	return ret;
>  }
Lad, Prabhakar March 10, 2021, 12:46 p.m. UTC | #2
Hi Laurent,

Thank you for the review.

On Wed, Mar 10, 2021 at 12:40 PM Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
>
> Hi Prabhakar,
>
> Thank you for the patch.
>
> On Wed, Mar 10, 2021 at 12:20:13PM +0000, Lad Prabhakar wrote:
> > Serialize during stream start/stop in suspend/resume callbacks.
>
> Could you please explain why this is needed ?
>
The streaming variable in this driver has serialized access, but this
wasn't taken care during suspend/resume callbacks.

Cheers,
Prabhakar

> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > ---
> >  drivers/media/i2c/imx219.c | 5 +++++
> >  1 file changed, 5 insertions(+)
> >
> > diff --git a/drivers/media/i2c/imx219.c b/drivers/media/i2c/imx219.c
> > index f0cf1985a4dc..87c021de1460 100644
> > --- a/drivers/media/i2c/imx219.c
> > +++ b/drivers/media/i2c/imx219.c
> > @@ -1172,8 +1172,10 @@ static int __maybe_unused imx219_suspend(struct device *dev)
> >       struct v4l2_subdev *sd = dev_get_drvdata(dev);
> >       struct imx219 *imx219 = to_imx219(sd);
> >
> > +     mutex_lock(&imx219->mutex);
> >       if (imx219->streaming)
> >               imx219_stop_streaming(imx219);
> > +     mutex_unlock(&imx219->mutex);
> >
> >       return 0;
> >  }
> > @@ -1184,11 +1186,13 @@ static int __maybe_unused imx219_resume(struct device *dev)
> >       struct imx219 *imx219 = to_imx219(sd);
> >       int ret;
> >
> > +     mutex_lock(&imx219->mutex);
> >       if (imx219->streaming) {
> >               ret = imx219_start_streaming(imx219);
> >               if (ret)
> >                       goto error;
> >       }
> > +     mutex_unlock(&imx219->mutex);
> >
> >       return 0;
> >
> > @@ -1197,6 +1201,7 @@ static int __maybe_unused imx219_resume(struct device *dev)
> >       imx219->streaming = false;
> >       __v4l2_ctrl_grab(imx219->vflip, false);
> >       __v4l2_ctrl_grab(imx219->hflip, false);
> > +     mutex_unlock(&imx219->mutex);
> >
> >       return ret;
> >  }
>
> --
> Regards,
>
> Laurent Pinchart
Laurent Pinchart March 10, 2021, 12:54 p.m. UTC | #3
Hi Prabhakar,

On Wed, Mar 10, 2021 at 12:46:39PM +0000, Lad, Prabhakar wrote:
> On Wed, Mar 10, 2021 at 12:40 PM Laurent Pinchart wrote:
> > On Wed, Mar 10, 2021 at 12:20:13PM +0000, Lad Prabhakar wrote:
> > > Serialize during stream start/stop in suspend/resume callbacks.
> >
> > Could you please explain why this is needed ?
> >
> The streaming variable in this driver has serialized access, but this
> wasn't taken care during suspend/resume callbacks.

But nothing that touches the streaming variable can run concurrently to
suspend/resume, isn't it ?

I'm actually even quite dubious about the need to start and stop
streaming during resume and suspend, the driver using the subdev should
start/stop the whole video pipeline at suspend/resume time.

> > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > > ---
> > >  drivers/media/i2c/imx219.c | 5 +++++
> > >  1 file changed, 5 insertions(+)
> > >
> > > diff --git a/drivers/media/i2c/imx219.c b/drivers/media/i2c/imx219.c
> > > index f0cf1985a4dc..87c021de1460 100644
> > > --- a/drivers/media/i2c/imx219.c
> > > +++ b/drivers/media/i2c/imx219.c
> > > @@ -1172,8 +1172,10 @@ static int __maybe_unused imx219_suspend(struct device *dev)
> > >       struct v4l2_subdev *sd = dev_get_drvdata(dev);
> > >       struct imx219 *imx219 = to_imx219(sd);
> > >
> > > +     mutex_lock(&imx219->mutex);
> > >       if (imx219->streaming)
> > >               imx219_stop_streaming(imx219);
> > > +     mutex_unlock(&imx219->mutex);
> > >
> > >       return 0;
> > >  }
> > > @@ -1184,11 +1186,13 @@ static int __maybe_unused imx219_resume(struct device *dev)
> > >       struct imx219 *imx219 = to_imx219(sd);
> > >       int ret;
> > >
> > > +     mutex_lock(&imx219->mutex);
> > >       if (imx219->streaming) {
> > >               ret = imx219_start_streaming(imx219);
> > >               if (ret)
> > >                       goto error;
> > >       }
> > > +     mutex_unlock(&imx219->mutex);
> > >
> > >       return 0;
> > >
> > > @@ -1197,6 +1201,7 @@ static int __maybe_unused imx219_resume(struct device *dev)
> > >       imx219->streaming = false;
> > >       __v4l2_ctrl_grab(imx219->vflip, false);
> > >       __v4l2_ctrl_grab(imx219->hflip, false);
> > > +     mutex_unlock(&imx219->mutex);
> > >
> > >       return ret;
> > >  }
Lad, Prabhakar March 10, 2021, 1:08 p.m. UTC | #4
Hi Laurent,

On Wed, Mar 10, 2021 at 12:54 PM Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
>
> Hi Prabhakar,
>
> On Wed, Mar 10, 2021 at 12:46:39PM +0000, Lad, Prabhakar wrote:
> > On Wed, Mar 10, 2021 at 12:40 PM Laurent Pinchart wrote:
> > > On Wed, Mar 10, 2021 at 12:20:13PM +0000, Lad Prabhakar wrote:
> > > > Serialize during stream start/stop in suspend/resume callbacks.
> > >
> > > Could you please explain why this is needed ?
> > >
> > The streaming variable in this driver has serialized access, but this
> > wasn't taken care during suspend/resume callbacks.
>
> But nothing that touches the streaming variable can run concurrently to
> suspend/resume, isn't it ?
>
You are right, we could drop this patch.

> I'm actually even quite dubious about the need to start and stop
> streaming during resume and suspend, the driver using the subdev should
> start/stop the whole video pipeline at suspend/resume time.
>
I see, do we have any documentation on how bridge/subdevs should
behave on suspend/resume ?

I did have a quick look at the omp3isp bridge driver and it does
start/stop on resume/suspend callbacks.

Cheers,
Prabhakar

> > > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > > > ---
> > > >  drivers/media/i2c/imx219.c | 5 +++++
> > > >  1 file changed, 5 insertions(+)
> > > >
> > > > diff --git a/drivers/media/i2c/imx219.c b/drivers/media/i2c/imx219.c
> > > > index f0cf1985a4dc..87c021de1460 100644
> > > > --- a/drivers/media/i2c/imx219.c
> > > > +++ b/drivers/media/i2c/imx219.c
> > > > @@ -1172,8 +1172,10 @@ static int __maybe_unused imx219_suspend(struct device *dev)
> > > >       struct v4l2_subdev *sd = dev_get_drvdata(dev);
> > > >       struct imx219 *imx219 = to_imx219(sd);
> > > >
> > > > +     mutex_lock(&imx219->mutex);
> > > >       if (imx219->streaming)
> > > >               imx219_stop_streaming(imx219);
> > > > +     mutex_unlock(&imx219->mutex);
> > > >
> > > >       return 0;
> > > >  }
> > > > @@ -1184,11 +1186,13 @@ static int __maybe_unused imx219_resume(struct device *dev)
> > > >       struct imx219 *imx219 = to_imx219(sd);
> > > >       int ret;
> > > >
> > > > +     mutex_lock(&imx219->mutex);
> > > >       if (imx219->streaming) {
> > > >               ret = imx219_start_streaming(imx219);
> > > >               if (ret)
> > > >                       goto error;
> > > >       }
> > > > +     mutex_unlock(&imx219->mutex);
> > > >
> > > >       return 0;
> > > >
> > > > @@ -1197,6 +1201,7 @@ static int __maybe_unused imx219_resume(struct device *dev)
> > > >       imx219->streaming = false;
> > > >       __v4l2_ctrl_grab(imx219->vflip, false);
> > > >       __v4l2_ctrl_grab(imx219->hflip, false);
> > > > +     mutex_unlock(&imx219->mutex);
> > > >
> > > >       return ret;
> > > >  }
>
> --
> Regards,
>
> Laurent Pinchart
diff mbox series

Patch

diff --git a/drivers/media/i2c/imx219.c b/drivers/media/i2c/imx219.c
index f0cf1985a4dc..87c021de1460 100644
--- a/drivers/media/i2c/imx219.c
+++ b/drivers/media/i2c/imx219.c
@@ -1172,8 +1172,10 @@  static int __maybe_unused imx219_suspend(struct device *dev)
 	struct v4l2_subdev *sd = dev_get_drvdata(dev);
 	struct imx219 *imx219 = to_imx219(sd);
 
+	mutex_lock(&imx219->mutex);
 	if (imx219->streaming)
 		imx219_stop_streaming(imx219);
+	mutex_unlock(&imx219->mutex);
 
 	return 0;
 }
@@ -1184,11 +1186,13 @@  static int __maybe_unused imx219_resume(struct device *dev)
 	struct imx219 *imx219 = to_imx219(sd);
 	int ret;
 
+	mutex_lock(&imx219->mutex);
 	if (imx219->streaming) {
 		ret = imx219_start_streaming(imx219);
 		if (ret)
 			goto error;
 	}
+	mutex_unlock(&imx219->mutex);
 
 	return 0;
 
@@ -1197,6 +1201,7 @@  static int __maybe_unused imx219_resume(struct device *dev)
 	imx219->streaming = false;
 	__v4l2_ctrl_grab(imx219->vflip, false);
 	__v4l2_ctrl_grab(imx219->hflip, false);
+	mutex_unlock(&imx219->mutex);
 
 	return ret;
 }