Messages in this thread Patch in this message |  | | Date | Fri, 27 Nov 2020 23:30:33 +0900 | From | Sergey Senozhatsky <> | Subject | Re: [PATCH] media: vb2: always set buffer cache sync hints |
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On (20/11/27 13:59), Hans Verkuil wrote: > > I think this needs a comment, basically explaining what you said in > the commit log. It's not obvious from the code that this is a > workaround.
Something like this?
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diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c index 5499013cf82e..21b2b0ae3629 100644 --- a/drivers/media/common/videobuf2/videobuf2-core.c +++ b/drivers/media/common/videobuf2/videobuf2-core.c @@ -414,6 +414,16 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory, vb->index = q->num_buffers + buffer; vb->type = q->type; vb->memory = memory; + /* + * A workaround fix. We need to set these flags here so that + * videobuf2 core will always call ->prepare()/->finish() + * cache sync/flush on vb2 buffers. Otherwise, for backends + * that don't rely on V4L2 (perhaps dvb) these flags will + * always be false and, hence, videobuf2 core will skip cache + * sync/flush operations. + */ + vb->need_cache_sync_on_prepare = 1; + vb->need_cache_sync_on_finish = 1; for (plane = 0; plane < num_planes; ++plane) { vb->planes[plane].length = plane_sizes[plane]; vb->planes[plane].min_length = plane_sizes[plane];
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