Messages in this thread | | | Date | Wed, 29 Nov 2023 14:40:27 +0100 | From | Paul Kocialkowski <> | Subject | Re: [PATCH 27/55] media: sun6i-isp: Stop abusing of min_buffers_needed field |
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Hi Benjamin,
On Mon 27 Nov 23, 17:54, Benjamin Gaignard wrote: > 'min_buffers_needed' is suppose to be used to indicate the number > of buffers needed by DMA engine to start streaming. > sun6i-isp 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.
The hardware actually has its own DMA engine. It can work with just one buffer though (which will never be returned to userspace). But I think we should still require at least two buffers allocated, otherwise the driver will be of no use at all.
So I don't think the commit message here is correct.
Cheers,
Paul
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com> > CC: Paul Kocialkowski <paul.kocialkowski@bootlin.com> > CC: Chen-Yu Tsai <wens@csie.org> > CC: Jernej Skrabec <jernej.skrabec@gmail.com> > CC: Samuel Holland <samuel@sholland.org> > CC: linux-sunxi@lists.linux.dev > --- > drivers/staging/media/sunxi/sun6i-isp/sun6i_isp_capture.c | 2 +- > drivers/staging/media/sunxi/sun6i-isp/sun6i_isp_params.c | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/staging/media/sunxi/sun6i-isp/sun6i_isp_capture.c b/drivers/staging/media/sunxi/sun6i-isp/sun6i_isp_capture.c > index 1595a9607775..f47f9946c19f 100644 > --- a/drivers/staging/media/sunxi/sun6i-isp/sun6i_isp_capture.c > +++ b/drivers/staging/media/sunxi/sun6i-isp/sun6i_isp_capture.c > @@ -660,7 +660,7 @@ int sun6i_isp_capture_setup(struct sun6i_isp_device *isp_dev) > queue->buf_struct_size = sizeof(struct sun6i_isp_buffer); > queue->ops = &sun6i_isp_capture_queue_ops; > queue->mem_ops = &vb2_dma_contig_memops; > - queue->min_buffers_needed = 2; > + queue->min_reqbufs_allocation = 2; > queue->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC; > queue->lock = &capture->lock; > queue->dev = isp_dev->dev; > diff --git a/drivers/staging/media/sunxi/sun6i-isp/sun6i_isp_params.c b/drivers/staging/media/sunxi/sun6i-isp/sun6i_isp_params.c > index e28be895b486..259f6bfcb620 100644 > --- a/drivers/staging/media/sunxi/sun6i-isp/sun6i_isp_params.c > +++ b/drivers/staging/media/sunxi/sun6i-isp/sun6i_isp_params.c > @@ -489,7 +489,7 @@ int sun6i_isp_params_setup(struct sun6i_isp_device *isp_dev) > queue->buf_struct_size = sizeof(struct sun6i_isp_buffer); > queue->ops = &sun6i_isp_params_queue_ops; > queue->mem_ops = &vb2_vmalloc_memops; > - queue->min_buffers_needed = 1; > + queue->min_reqbufs_allocation = 1; > queue->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC; > queue->lock = ¶ms->lock; > queue->dev = isp_dev->dev; > -- > 2.39.2 >
-- Paul Kocialkowski, Bootlin Embedded Linux and kernel engineering https://bootlin.com [unhandled content-type:application/pgp-signature] | |