Re: [PATCH v2 1/2] media: nxp: imx8-isi: Reduce minimum queued buffers from 2 to 0
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: 2026-03-19 21:48:35
Also in:
imx, linux-media, lkml, stable
Hi Guoniu, Thank you for the patch. On Thu, Mar 12, 2026 at 11:12:34AM +0800, Guoniu Zhou wrote:
quoted hunk ↗ jump to hunk
From: Guoniu Zhou <redacted> Fix a hang issue when capturing a single frame with applications like cam in libcamera. It would hang waiting for the driver to complete the buffer, but streaming never starts because min_queued_buffers was set to 2. The ISI module uses a ping-pong buffer mechanism that requires two buffers to be programmed at all times. However, when fewer than 2 user buffers are available, the driver use internal discard buffers to fill the remaining slot(s). Reduce minimum queued buffers from 2 to 0 allows streaming to start without any queued buffers. Fixes: cf21f328fcaf ("media: nxp: Add i.MX8 ISI driver") Cc: stable@vger.kernel.org Signed-off-by: Guoniu Zhou <redacted> --- Changes in v2: - Reduce min_queued_buffers from 2 to 0 suggested by Jacopo Mondi https://lore.kernel.org/linux-media/20260311-isi_min_buffers-v1-0-c9299d6e8ae6@nxp.com/T/#mcd4b7dcc218a02e2f218ba2c83b947ccefd9308b (local) - Add fix tag --- drivers/media/platform/nxp/imx8-isi/imx8-isi-video.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/drivers/media/platform/nxp/imx8-isi/imx8-isi-video.c b/drivers/media/platform/nxp/imx8-isi/imx8-isi-video.c index 13682bf6e9f8895bb9eb1f92d5f74b0d5968544e..1be3a728f32f89338a75ddcc4e96e7501ed954e1 100644 --- a/drivers/media/platform/nxp/imx8-isi/imx8-isi-video.c +++ b/drivers/media/platform/nxp/imx8-isi/imx8-isi-video.c@@ -1410,7 +1410,7 @@ int mxc_isi_video_register(struct mxc_isi_pipe *pipe, q->mem_ops = &vb2_dma_contig_memops; q->buf_struct_size = sizeof(struct mxc_isi_buffer); q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC; - q->min_queued_buffers = 2; + q->min_queued_buffers = 0;
A simple way to fix the issue, that's nice. Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
q->lock = &video->lock; q->dev = pipe->isi->dev;
-- Regards, Laurent Pinchart