[PATCH 4.9 33/46] Revert "media: videobuf2-core: dont call memop finish when queueing"

From: Greg Kroah-Hartman
Date: Mon Nov 26 2018 - 05:58:53 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

This reverts commit 9ac47200b51cb09d2f15dbefa67e0412741d98aa.

This commit fixes a bug in upstream commit a136f59c0a1f ("vb2: Move
buffer cache synchronisation to prepare from queue") which isn't
present in 4.9.

So as a result you get an UNBALANCED message in the kernel log if
this patch is applied:

vb2: counters for queue ffffffc0f3687478, buffer 3: UNBALANCED!
vb2: buf_init: 1 buf_cleanup: 1 buf_prepare: 805 buf_finish: 805
vb2: buf_queue: 806 buf_done: 806
vb2: alloc: 0 put: 0 prepare: 806 finish: 805 mmap: 0
vb2: get_userptr: 0 put_userptr: 0
vb2: attach_dmabuf: 1 detach_dmabuf: 1 map_dmabuf: 805 unmap_dmabuf: 805
vb2: get_dmabuf: 0 num_users: 1609 vaddr: 0 cookie: 805

Reverting this patch solves this regression.

Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/media/v4l2-core/videobuf2-core.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index f7ca1fab4808..4df4a1f402be 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -914,12 +914,9 @@ void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
dprintk(4, "done processing on buffer %d, state: %d\n",
vb->index, state);

- if (state != VB2_BUF_STATE_QUEUED &&
- state != VB2_BUF_STATE_REQUEUEING) {
- /* sync buffers */
- for (plane = 0; plane < vb->num_planes; ++plane)
- call_void_memop(vb, finish, vb->planes[plane].mem_priv);
- }
+ /* sync buffers */
+ for (plane = 0; plane < vb->num_planes; ++plane)
+ call_void_memop(vb, finish, vb->planes[plane].mem_priv);

spin_lock_irqsave(&q->done_lock, flags);
if (state == VB2_BUF_STATE_QUEUED ||
--
2.17.1