Re: [PATCH v14 26/56] media: i2c: video-i2c: Stop direct calls to queue num_buffers field

Andrzej Pietrasiewicz
2023-11-09T10:18:57Z

Hi Benjamin,

W dniu 31.10.2023 o 17:30, Benjamin Gaignard pisze:
> Use vb2_get_num_buffers() to avoid using queue num_buffers field directly.
> This allows us to change how the number of buffers is computed in the
> future.
>
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
> CC: Matt Ranostay <matt.ranostay@konsulko.com>
> ---
> drivers/media/i2c/video-i2c.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/i2c/video-i2c.c b/drivers/media/i2c/video-i2c.c
> index 178bd06cc2ed..ebf2ac98a068 100644
> --- a/drivers/media/i2c/video-i2c.c
> +++ b/drivers/media/i2c/video-i2c.c
> @@ -405,9 +405,10 @@ static int queue_setup(struct vb2_queue *vq,
> {
> struct video_i2c_data *data = vb2_get_drv_priv(vq);
> unsigned int size = data->chip->buffer_size;
> + unsigned int q_num_bufs = vb2_get_num_buffers(vq);
>
> - if (vq->num_buffers + *nbuffers < 2)
> - *nbuffers = 2;
> + if (q_num_bufs + *nbuffers < 2)
> + *nbuffers = 2 - q_num_bufs;

This actually changes the logic. Maybe it has already been discussed and
the result of that discussion is this change in logic? Looking at other
drivers *nbuffers = 2 - q_num_bufs; seems the right thing to do.
But then at least the commit message body IMO should mention this change.
Or, preferably, the change in logic should be a separate patch to be applied
before this one.

Regards,

Andrzej

>
> if (*nplanes)
> return sizes[0] < size ? -EINVAL : 0;