[PATCH AUTOSEL 4.19 2/4] media: vb2: use lock if wait_prepare/finish are NULL

[Sasha Levin <sashal@kernel.org>]

From: Hans Verkuil <hverkuil-cisco@xs4all.nl>

[ Upstream commit 88785982a19daa765e30ab3a605680202cfaee4e ]

If the wait_prepare or wait_finish callback is set, then call it.
If it is NULL and the queue lock pointer is not NULL, then just
unlock/lock that mutex.

This allows simplifying drivers by dropping the wait_prepare and
wait_finish ops (and eventually the vb2_ops_wait_prepare/finish helpers).

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/media/common/videobuf2/videobuf2-core.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index 98719aa986bb9..e439831f6df46 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -1528,7 +1528,10 @@ static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
 		 * become ready or for streamoff. Driver's lock is released to
 		 * allow streamoff or qbuf to be called while waiting.
 		 */
-		call_void_qop(q, wait_prepare, q);
+		if (q->ops->wait_prepare)
+			call_void_qop(q, wait_prepare, q);
+		else if (q->lock)
+			mutex_unlock(q->lock);
 
 		/*
 		 * All locks have been released, it is safe to sleep now.
@@ -1538,12 +1541,16 @@ static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
 				!list_empty(&q->done_list) || !q->streaming ||
 				q->error);
 
+		if (q->ops->wait_finish)
+			call_void_qop(q, wait_finish, q);
+		else if (q->lock)
+			mutex_lock(q->lock);
+
+		q->waiting_in_dqbuf = 0;
 		/*
 		 * We need to reevaluate both conditions again after reacquiring
 		 * the locks or return an error if one occurred.
 		 */
-		call_void_qop(q, wait_finish, q);
-		q->waiting_in_dqbuf = 0;
 		if (ret) {
 			dprintk(1, "sleep was interrupted\n");
 			return ret;
-- 
2.43.0