Re: [PATCH v2 33/36] media: ti: cal: Fix misuse of min_buffers_needed field

From: Hans Verkuil
Date: Mon Dec 04 2023 - 10:10:28 EST


On 04/12/2023 14:23, Benjamin Gaignard wrote:
> 'min_buffers_needed' is suppose to be used to indicate the number
> of buffers needed by DMA engine to start streaming.
> Cal driver doesn't use DMA engine and just want to specify
> the minimum number of buffers to allocate when calling VIDIOC_REQBUFS.
> That 'min_reqbufs_allocation' field purpose so use it.
>
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>
> CC: Benoit Parrot <bparrot@xxxxxx>
> ---
> drivers/media/platform/ti/cal/cal-video.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/media/platform/ti/cal/cal-video.c b/drivers/media/platform/ti/cal/cal-video.c
> index e1c5e68e945b..04709dac7221 100644
> --- a/drivers/media/platform/ti/cal/cal-video.c
> +++ b/drivers/media/platform/ti/cal/cal-video.c
> @@ -1010,7 +1010,7 @@ int cal_ctx_v4l2_init(struct cal_ctx *ctx)
> q->mem_ops = &vb2_dma_contig_memops;
> q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
> q->lock = &ctx->mutex;
> - q->min_buffers_needed = 3;
> + q->min_reqbufs_allocation = 3;
> q->dev = ctx->cal->dev;
>
> ret = vb2_queue_init(q);

This driver definitely needs 1 buffer before it can start DMA, so set
min_buffers_needed to 1.

Regards,

Hans