V4L/DVB (6944a): Fix Regression VIDIOCGMBUF ioctl hangs on bttv driver

Fix bttv VIDIOCGMBUF locking like done in commit
820eacd84cff23b76693f4be1e28feb672f4488f. 

Signed-off-by: Gregor Jasny <gjasny@web.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

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 c02d92deacd2..581a3c955739 100644
--- a/drivers/media/video/bt8xx/bttv-driver.c
+++ b/drivers/media/video/bt8xx/bttv-driver.c
@@ -3063,11 +3063,10 @@ static int bttv_do_ioctl(struct inode *inode, struct file *file,
                 struct video_mbuf *mbuf = arg;
                 unsigned int i;
 
-                mutex_lock(&fh->cap.lock);
                 retval = videobuf_mmap_setup(&fh->cap,gbuffers,gbufsize,
                                              V4L2_MEMORY_MMAP);
                 if (retval < 0)
-                        goto fh_unlock_and_return;
+                        return retval;
 
                 gbuffers = retval;
                 memset(mbuf,0,sizeof(*mbuf));
@@ -3075,7 +3074,6 @@ static int bttv_do_ioctl(struct inode *inode, struct file *file,
                 mbuf->size   = gbuffers * gbufsize;
                 for (i = 0; i < gbuffers; i++)
                         mbuf->offsets[i] = i * gbufsize;
-                mutex_unlock(&fh->cap.lock);
                 return 0;
         }
         case VIDIOCMCAPTURE: