Re: [PATCH] media: rcar-vin: Drop min_queued_buffers

From: Laurent Pinchart

Date: Tue May 26 2026 - 12:39:12 EST


Hi Jacopo,

Thank you for the patch.

On Mon, May 04, 2026 at 02:43:14PM +0200, Jacopo Mondi wrote:
> From: Jacopo Mondi <jacopo.mondi+renesas@xxxxxxxxxxxxxxxx>
>
> The R-Car VIN driver already uses a scratch buffer to sustain capture
> operations in absence of a frame buffer provided by userspace.
>
> There is no reason to require 4 buffers queued at all times for the
> driver to operate. Drop min_queued_buffers from the VIN driver to allow
> single-frame capture operations.
>
> Signed-off-by: Jacopo Mondi <jacopo.mondi+renesas@xxxxxxxxxxxxxxxx>

Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>

> ---
> This allows to capture a single frame when the R-Car VIN is used
> to feed the R-Car ISP on R-Car V4H.
>
> Signed-off-by: Jacopo Mondi <jacopo.mondi@xxxxxxxxxxxxxxxx>
> ---
> drivers/media/platform/renesas/rcar-vin/rcar-dma.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/drivers/media/platform/renesas/rcar-vin/rcar-dma.c b/drivers/media/platform/renesas/rcar-vin/rcar-dma.c
> index f9af9177e02f..73cda0e2d45a 100644
> --- a/drivers/media/platform/renesas/rcar-vin/rcar-dma.c
> +++ b/drivers/media/platform/renesas/rcar-vin/rcar-dma.c
> @@ -1494,7 +1494,6 @@ int rvin_dma_register(struct rvin_dev *vin, int irq)
> q->ops = &rvin_qops;
> q->mem_ops = &vb2_dma_contig_memops;
> q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
> - q->min_queued_buffers = 4;
> q->dev = vin->dev;
>
> ret = vb2_queue_init(q);
>
> ---
> base-commit: d9c8c4adf23d17549c0ec9c85b99d85a0ee6cf18
> change-id: 20260504-rcar-vin-min-queued-buffs-31891f226fe6

--
Regards,

Laurent Pinchart