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| author | Pawel Osciak <posciak@chromium.org> | 2019-01-24 12:51:55 +0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-01-31 14:28:44 +0300 |
| commit | 2cc1802f62e562611e86f04d9dae1337c824991e (patch) | |
| tree | 1f79b20a16b9036a30bda8e6fd76ccbc0b83a5a6 /drivers/media/common | |
| parent | 826ef7508833f8bae928ccae4071b6efa6ba6184 (diff) | |
| download | linux-2cc1802f62e562611e86f04d9dae1337c824991e.tar.xz | |
media: vb2: Keep dma-buf buffers mapped until they are freed
When using vb2 for video decoding, dequeued capture buffers may still
be accessed by the hardware: this is the case when they are used as
reference frames for decoding subsequent frames.
When the buffer is imported with dma-buf, it needs to be mapped before
access. Until now, it was mapped when queuing and unmapped when
dequeuing, which doesn't work for access as a reference frames.
One way to solve this would be to map the buffer again when it is
needed as a reference, but the mapping/unmapping operations can
seriously impact performance. As a result, map the buffer once (when it
is first needed when queued) and keep it mapped until it is freed.
Reviewed-on: https://chromium-review.googlesource.com/334103
[Paul: Updated for mainline and changed commit message]
Signed-off-by: Pawel Osciak <posciak@chromium.org>
Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Diffstat (limited to 'drivers/media/common')
| -rw-r--r-- | drivers/media/common/videobuf2/videobuf2-core.c | 11 |
1 files changed, 3 insertions, 8 deletions
diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c index 70e8c3366f9c..ce9294a635cc 100644 --- a/drivers/media/common/videobuf2/videobuf2-core.c +++ b/drivers/media/common/videobuf2/videobuf2-core.c @@ -1196,6 +1196,9 @@ static int __prepare_dmabuf(struct vb2_buffer *vb) * userspace knows sooner rather than later if the dma-buf map fails. */ for (plane = 0; plane < vb->num_planes; ++plane) { + if (vb->planes[plane].dbuf_mapped) + continue; + ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv); if (ret) { dprintk(1, "failed to map dmabuf for plane %d\n", @@ -1758,14 +1761,6 @@ static void __vb2_dqbuf(struct vb2_buffer *vb) vb->state = VB2_BUF_STATE_DEQUEUED; - /* unmap DMABUF buffer */ - if (q->memory == VB2_MEMORY_DMABUF) - for (i = 0; i < vb->num_planes; ++i) { - if (!vb->planes[i].dbuf_mapped) - continue; - call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv); - vb->planes[i].dbuf_mapped = 0; - } call_void_bufop(q, init_buffer, vb); } |