Hi Laurent,
On Thu, Jun 08, 2023 at 03:48:30PM +0300, Laurent Pinchart wrote:
> Hi Sakari,
>
> On Thu, Jun 08, 2023 at 12:44:51PM +0000, Sakari Ailus wrote:
> > On Wed, Jun 07, 2023 at 06:46:49PM +0200, Hans de Goede wrote:
> > > On ov2680_set_fmt() calls with format->which == V4L2_SUBDEV_FORMAT_TRY,
> > > ov2680_set_fmt() does not talk to the sensor.
> > >
> > > So in this case there is no need to lock the sensor->lock mutex or
> > > to check that the sensor is streaming.
> > >
> > > Fixes: 3ee47cad3e69 ("media: ov2680: Add Omnivision OV2680 sensor driver")
> > > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> > > ---
> > > drivers/media/i2c/ov2680.c | 20 +++++++++-----------
> > > 1 file changed, 9 insertions(+), 11 deletions(-)
> > >
> > > diff --git a/drivers/media/i2c/ov2680.c b/drivers/media/i2c/ov2680.c
> > > index d90bbca6e913..a26a6f18f4f1 100644
> > > --- a/drivers/media/i2c/ov2680.c
> > > +++ b/drivers/media/i2c/ov2680.c
> > > @@ -592,24 +592,22 @@ static int ov2680_set_fmt(struct v4l2_subdev *sd,
> > > if (format->pad != 0)
> > > return -EINVAL;
> > >
> > > - mutex_lock(&sensor->lock);
> > > -
> > > - if (sensor->is_streaming) {
> > > - ret = -EBUSY;
> > > - goto unlock;
> > > - }
> > > -
> > > mode = v4l2_find_nearest_size(ov2680_mode_data,
> > > ARRAY_SIZE(ov2680_mode_data), width,
> > > height, fmt->width, fmt->height);
> > > - if (!mode) {
> > > - ret = -EINVAL;
> > > - goto unlock;
> > > - }
> > > + if (!mode)
> > > + return -EINVAL;
> > >
> > > if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
> > > try_fmt = v4l2_subdev_get_try_format(sd, sd_state, 0);
> > > format->format = *try_fmt;
> >
> > Access to sd_state needs to be serialised, so mutex should be held here.
>
> This operation should be called with the state lock held already, so I
> don't think any extra locking is needed.
Ah, you're right indeed. I suppose lock here is redundant but controls need
some care.
--
Regards,
Sakari Ailus
