On Sat, Jun 20, 2020 at 03:48:04PM +0800, Dongchun Zhu wrote:
> Hi Tomasz,
>
> Thanks for the review.
>
> On Thu, 2020-06-18 at 19:10 +0000, Tomasz Figa wrote:
> > Hi Dongchun,
> >
> > On Mon, Jun 15, 2020 at 08:29:37PM +0800, Dongchun Zhu wrote:
> > > Add a V4L2 sub-device driver for OV02A10 image sensor.
> > >
> > > Signed-off-by: Dongchun Zhu <dongchun.zhu@xxxxxxxxxxxx>
> > > ---
> > > MAINTAINERS | 1 +
> > > drivers/media/i2c/Kconfig | 13 +
> > > drivers/media/i2c/Makefile | 1 +
> > > drivers/media/i2c/ov02a10.c | 1042 +++++++++++++++++++++++++++++++++++++++++++
> > > 4 files changed, 1057 insertions(+)
> > > create mode 100644 drivers/media/i2c/ov02a10.c
> > >
> >
> > Thank you for the patch. Please see my comments inline.
> >
> > [snip]
> > > +static int ov02a10_set_fmt(struct v4l2_subdev *sd,
> > > + struct v4l2_subdev_pad_config *cfg,
> > > + struct v4l2_subdev_format *fmt)
> > > +{
> > > + struct ov02a10 *ov02a10 = to_ov02a10(sd);
> > > + struct v4l2_mbus_framefmt *mbus_fmt = &fmt->format;
> > > +
> > > + mutex_lock(&ov02a10->mutex);
> > > +
> > > + if (ov02a10->streaming) {
> > > + mutex_unlock(&ov02a10->mutex);
> > > + return -EBUSY;
> > > + }
> > > +
> > > + /* Only one sensor mode supported */
> > > + mbus_fmt->code = ov02a10->fmt.code;
> > > + ov02a10_fill_fmt(ov02a10->cur_mode, mbus_fmt);
> > > + ov02a10->fmt = fmt->format;
> > > +
> > > + if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
> > > + *v4l2_subdev_get_try_format(sd, cfg, fmt->pad) = fmt->format;
> >
> > If fmt->which is V4L2_SUBDEV_FORMAT_TRY, the internal driver state must not
> > be affected. It also should not depend on whether the sensor is streaming
> > or not. Basically it should be considered a special "candidate" format,
> > which isn't programmed to the hardware, but just stored aside.
> >
>
> Hmm. Maybe we shall use FORMAT_TRY like this:
> struct v4l2_mbus_framefmt *frame_fmt;
> ...
> if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
> frame_fmt = v4l2_subdev_get_try_format(sd, cfg, 0);
> else
> frame_fmt = &ov02a10->fmt;
>
> *frame_fmt = *mbus_fmt;
>
> (Remove 'ov02a10->fmt = fmt->format;' above)
>
Yes, I guess that should work. Also the ov02a10->streaming condition
shouldn't be checked if fmt->which is V4L2_SUBDEV_FORMAT_TRY).
Best regards,
Tomasz
