Hello Laurent,
2011/9/5 Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>:
> Hi Bastian,
>
> On Monday 05 September 2011 11:41:28 Bastian Hecht wrote:
>> 2011/9/5 Laurent Pinchart:
>> > On Monday 05 September 2011 11:10:48 Bastian Hecht wrote:
>> >> 2011/8/31 Laurent Pinchart:
>> >> >> > static int ov5642_g_crop(struct v4l2_subdev *sd, struct v4l2_crop
>> >> >> > *a) {
>> >> >> >
>> >> >> > + struct i2c_client *client = v4l2_get_subdevdata(sd);
>> >> >> > + struct ov5642 *priv = to_ov5642(client);
>> >> >> >
>> >> >> > struct v4l2_rect *rect = &a->c;
>> >> >> >
>> >> >> > - a->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
>> >> >> > - rect->top = 0;
>> >> >> > - rect->left = 0;
>> >> >> > - rect->width = OV5642_WIDTH;
>> >> >> > - rect->height = OV5642_HEIGHT;
>> >> >> > + a->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
>> >> >>
>> >> >> Shouldn't you return an error instead when a->type is not
>> >> >> V4L2_BUF_TYPE_VIDEO_CAPTURE ?
>> >>
>> >> No idea, but if you say so, I'll change it.
>> >
>> > VIDIOC_G_FMT documentation states that
>> >
>> > "When the requested buffer type is not supported drivers return an EINVAL
>> > error code."
>> >
>> > I thought VIDIOC_G_CROP documentation did as well, but it doesn't.
>> > However I believe the above should apply to VIDIOC_G_CROP as well. There
>> > is no explicit documentation about error codes for subdev operations,
>> > but I think it makes sense to follow what the V4L2 ioctls do.
>>
>> And these ioctl calls go straight through to my driver? Or is there
>> some intermediate work by the subdev architecture? I'm asking because
>> I don't check the buffer type in g_fmt as well. If so, I have to
>> change that too.
>
> The ioctls go to the host/bridge driver, which then decides when and how to
> call g/s_fmt and g/s_crop. I would add the same check to g_fmt.
Next time I will work in the media section of the kernel, I must study
the docs a bit better I guess :/
To the g_fmt() thing... is there the buffer type given at all? The
argument of type struct v4l2_mbus_framefmt doesn't contain it.
best,
Bastian
> --
> Regards,
>
> Laurent Pinchart
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