V4L/DVB: bttv: Fix mutex unbalance at bttv_poll

Don't do double mutex_unlock when reading a stream at bttv_poll.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 1 insertions, 3 deletions

diff --git a/drivers/media/video/bt8xx/bttv-driver.c b/drivers/media/video/bt8xx/bttv-driver.c
index fcafe2f1e5cf..d74dfa6d1a55 100644
--- a/drivers/media/video/bt8xx/bttv-driver.c
+++ b/drivers/media/video/bt8xx/bttv-driver.c
@@ -3162,15 +3162,14 @@ static unsigned int bttv_poll(struct file *file, poll_table *wait)
                 return videobuf_poll_stream(file, &fh->vbi, wait);
         }
 
+        mutex_lock(&fh->cap.vb_lock);
         if (check_btres(fh,RESOURCE_VIDEO_STREAM)) {
-                mutex_lock(&fh->cap.vb_lock);
                 /* streaming capture */
                 if (list_empty(&fh->cap.stream))
                         goto err;
                 buf = list_entry(fh->cap.stream.next,struct bttv_buffer,vb.stream);
         } else {
                 /* read() capture */
-                mutex_lock(&fh->cap.vb_lock);
                 if (NULL == fh->cap.read_buf) {
                         /* need to capture a new frame */
                         if (locked_btres(fh->btv,RESOURCE_VIDEO_STREAM))
@@ -3188,7 +3187,6 @@ static unsigned int bttv_poll(struct file *file, poll_table *wait)
                         fh->cap.ops->buf_queue(&fh->cap,fh->cap.read_buf);
                         fh->cap.read_off = 0;
                 }
-                mutex_unlock(&fh->cap.vb_lock);
                 buf = (struct bttv_buffer*)fh->cap.read_buf;
         }