V4L/DVB: videobuf: prepare to make locking optional in videobuf

Currently videobuf uses the vb_lock mutex to lock its data structures.
But this locking will (optionally) move into the v4l2 core, which means
that in that case vb_lock shouldn't be used since the external lock is already
held.

Prepare for this by adding a pointer to such an external mutex and
don't lock if that pointer is set.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/media/video/videobuf-dma-sg.c b/drivers/media/video/videobuf-dma-sg.c
index 2ad0bc252b0e..515ae887ffcf 100644
--- a/drivers/media/video/videobuf-dma-sg.c
+++ b/drivers/media/video/videobuf-dma-sg.c
@@ -358,7 +358,7 @@ static void videobuf_vm_close(struct vm_area_struct *vma)
         map->count--;
         if (0 == map->count) {
                 dprintk(1, "munmap %p q=%p\n", map, q);
-                mutex_lock(&q->vb_lock);
+                videobuf_queue_lock(q);
                 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
                         if (NULL == q->bufs[i])
                                 continue;
@@ -374,7 +374,7 @@ static void videobuf_vm_close(struct vm_area_struct *vma)
                         q->bufs[i]->baddr = 0;
                         q->ops->buf_release(q, q->bufs[i]);
                 }
-                mutex_unlock(&q->vb_lock);
+                videobuf_queue_unlock(q);
                 kfree(map);
         }
         return;