Re: [PATCH v7 23/49] media: pci: cx18: Stop direct calls to queue num_buffers field

Hans Verkuil
2023-09-19T13:43:01Z

On 14/09/2023 15:32, Benjamin Gaignard wrote:
> Use vb2_get_num_buffers() to avoid using queue num_buffer field directly.
>
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
> ---
> drivers/media/pci/cx18/cx18-streams.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/pci/cx18/cx18-streams.c b/drivers/media/pci/cx18/cx18-streams.c
> index 597472754c4c..a7a7e006b3be 100644
> --- a/drivers/media/pci/cx18/cx18-streams.c
> +++ b/drivers/media/pci/cx18/cx18-streams.c
> @@ -105,6 +105,7 @@ static int cx18_queue_setup(struct vb2_queue *vq,
> unsigned int sizes[], struct device *alloc_devs[])
> {
> struct cx18_stream *s = vb2_get_drv_priv(vq);
> + unsigned int q_num_bufs = vb2_get_num_buffers(vq);
> struct cx18 *cx = s->cx;
> unsigned int szimage;
>
> @@ -121,8 +122,8 @@ static int cx18_queue_setup(struct vb2_queue *vq,
> * Let's request at least three buffers: two for the
> * DMA engine and one for userspace.
> */
> - if (vq->num_buffers + *nbuffers < 3)
> - *nbuffers = 3 - vq->num_buffers;
> + if (q_num_bufs + *nbuffers < 3)
> + *nbuffers = 3 - q_num_bufs;

From what I can see, this driver already sets min_buffers_needed to 3,
so this check can just be dropped.

Hans

>
> if (*nplanes) {
> if (*nplanes != 1 || sizes[0] < szimage)