From f5f5fa73fbfb9f346f1b5f37ebf343bae6ef6361 Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Thu, 14 May 2020 18:01:42 +0200 Subject: media: videobuf2: handle V4L2 buffer cache flags Set video buffer cache management flags corresponding to V4L2 cache flags. Both ->prepare() and ->finish() cache management hints should be passed during this stage (buffer preparation), because there is no other way for user-space to tell V4L2 to avoid ->finish() cache flush. Signed-off-by: Sergey Senozhatsky Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/common/videobuf2/videobuf2-v4l2.c | 48 +++++++++++++++++++++++++ 1 file changed, 48 insertions(+) (limited to 'drivers/media/common') diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c index eb5d5db96552..f13851212cc8 100644 --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c @@ -337,6 +337,53 @@ static int vb2_fill_vb2_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b return 0; } +static void set_buffer_cache_hints(struct vb2_queue *q, + struct vb2_buffer *vb, + struct v4l2_buffer *b) +{ + /* + * DMA exporter should take care of cache syncs, so we can avoid + * explicit ->prepare()/->finish() syncs. For other ->memory types + * we always need ->prepare() or/and ->finish() cache sync. + */ + if (q->memory == VB2_MEMORY_DMABUF) { + vb->need_cache_sync_on_finish = 0; + vb->need_cache_sync_on_prepare = 0; + return; + } + + /* + * Cache sync/invalidation flags are set by default in order to + * preserve existing behaviour for old apps/drivers. + */ + vb->need_cache_sync_on_prepare = 1; + vb->need_cache_sync_on_finish = 1; + + if (!vb2_queue_allows_cache_hints(q)) { + /* + * Clear buffer cache flags if queue does not support user + * space hints. That's to indicate to userspace that these + * flags won't work. + */ + b->flags &= ~V4L2_BUF_FLAG_NO_CACHE_INVALIDATE; + b->flags &= ~V4L2_BUF_FLAG_NO_CACHE_CLEAN; + return; + } + + /* + * ->finish() cache sync can be avoided when queue direction is + * TO_DEVICE. + */ + if (q->dma_dir == DMA_TO_DEVICE) + vb->need_cache_sync_on_finish = 0; + + if (b->flags & V4L2_BUF_FLAG_NO_CACHE_INVALIDATE) + vb->need_cache_sync_on_finish = 0; + + if (b->flags & V4L2_BUF_FLAG_NO_CACHE_CLEAN) + vb->need_cache_sync_on_prepare = 0; +} + static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *mdev, struct v4l2_buffer *b, bool is_prepare, struct media_request **p_req) @@ -381,6 +428,7 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *md } if (!vb->prepared) { + set_buffer_cache_hints(q, vb, b); /* Copy relevant information provided by the userspace */ memset(vbuf->planes, 0, sizeof(vbuf->planes[0]) * vb->num_planes); -- cgit v1.2.3