[media] vb2: push the mmap semaphore down to __buf_prepare()
Rather than taking the mmap semaphore at a relatively high-level function,
push it down to the place where it is really needed.
It was placed in vb2_queue_or_prepare_buf() to prevent racing with other
vb2 calls. The only way I can see that a race can happen is when two
threads queue the same buffer. The solution for that it to introduce
a PREPARING state.
Moving it down offers opportunities to simplify the code.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 0ae974e..ea76652 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -142,6 +142,7 @@
/**
* enum vb2_buffer_state - current video buffer state
* @VB2_BUF_STATE_DEQUEUED: buffer under userspace control
+ * @VB2_BUF_STATE_PREPARING: buffer is being prepared in videobuf
* @VB2_BUF_STATE_PREPARED: buffer prepared in videobuf and by the driver
* @VB2_BUF_STATE_QUEUED: buffer queued in videobuf, but not in driver
* @VB2_BUF_STATE_ACTIVE: buffer queued in driver and possibly used
@@ -154,6 +155,7 @@
*/
enum vb2_buffer_state {
VB2_BUF_STATE_DEQUEUED,
+ VB2_BUF_STATE_PREPARING,
VB2_BUF_STATE_PREPARED,
VB2_BUF_STATE_QUEUED,
VB2_BUF_STATE_ACTIVE,