[media.git/next] media: rkisp1: Reduce min_queued_buffers to 1

[media-ci]

On Mon Oct 7 14:42:24 2024 +0200, Jacopo Mondi wrote:
> There apparently is no reason to require 3 queued buffers to call
> streamon() for the RkISP1 as the driver operates with a scratch buffer
> where frames can be directed to if there's no available buffer provided
> by userspace.
> 
> Reduce the number of required buffers to 1 to allow applications to
> operate with a single queued buffer.
> 
> Tested with libcamera, by operating with a single capture request. The
> same request (and associated capture buffer) gets recycled once
> completed. This of course causes a frame rate drop but doesn't hinder
> operations.
> 
> Signed-off-by: Jacopo Mondi <jacopo.mo...@ideasonboard.com>
> Reviewed-by: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
> Link: 
> https://lore.kernel.org/r/20241007124225.63463-1-jacopo.mo...@ideasonboard.com
> Signed-off-by: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
> Signed-off-by: Mauro Carvalho Chehab <mchehab+hua...@kernel.org>

Patch committed.

Thanks,
Mauro Carvalho Chehab

 drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

---

diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c 
b/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c
index 02339cd94486..6dcefd144d5a 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c
@@ -35,8 +35,6 @@
 #define RKISP1_SP_DEV_NAME     RKISP1_DRIVER_NAME "_selfpath"
 #define RKISP1_MP_DEV_NAME     RKISP1_DRIVER_NAME "_mainpath"
 
-#define RKISP1_MIN_BUFFERS_NEEDED 3
-
 enum rkisp1_plane {
        RKISP1_PLANE_Y  = 0,
        RKISP1_PLANE_CB = 1,
@@ -1561,7 +1559,7 @@ static int rkisp1_register_capture(struct rkisp1_capture 
*cap)
        q->ops = &rkisp1_vb2_ops;
        q->mem_ops = &vb2_dma_contig_memops;
        q->buf_struct_size = sizeof(struct rkisp1_buffer);
-       q->min_queued_buffers = RKISP1_MIN_BUFFERS_NEEDED;
+       q->min_queued_buffers = 1;
        q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
        q->lock = &node->vlock;
        q->dev = cap->rkisp1->dev;