Jun 29 2010

V4L/DVB: drivers/media/video/pvrusb2: Add missing mutex_unlock 

Author: Julia Lawall <julia@diku.dk>

Add a mutex_unlock missing on the error path.  In the other functions in
the same file the locks and unlocks of this mutex appear to be balanced,
so it would seem that the same should hold in this case.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// 
@@
expression E1;
@@

* mutex_lock(E1,...);
  <+... when != E1
  if (...) {
    ... when != E1
*   return ...;
  }
  ...+>
* mutex_unlock(E1,...);
// 

Signed-off-by: Julia Lawall 
Signed-off-by: Douglas Schilling Landgraf 
Signed-off-by: Mauro Carvalho Chehab 

---
 drivers/media/video/pvrusb2/pvrusb2-ioread.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
 
diff --git a/drivers/media/video/pvrusb2/pvrusb2-ioread.c b/drivers/media/video/pvrusb2/pvrusb2-ioread.c
index b482478..bba6115 100644
--- a/drivers/media/video/pvrusb2/pvrusb2-ioread.c
+++ b/drivers/media/video/pvrusb2/pvrusb2-ioread.c
@@ -223,7 +223,10 @@ int pvr2_ioread_setup(struct pvr2_ioread *cp,struct pvr2_stream *sp)
 				   " pvr2_ioread_setup (setup) id=%p",cp);
 			pvr2_stream_kill(sp);
 			ret = pvr2_stream_set_buffer_count(sp,BUFFER_COUNT);
-			if (ret < 0) return ret;
+			if (ret < 0) {
+				mutex_unlock(&cp->mutex);
+				return ret;
+			}
 			for (idx = 0; idx < BUFFER_COUNT; idx++) {
 				bp = pvr2_stream_get_buffer(sp,idx);
 				pvr2_buffer_set_buffer(bp,

qlambert