msm: camera: Allow driver file to be opend only once.

Use proper synchronization to ensure driver file is opened only once. FPIIM-1557 CRs-Fixed: 2023513 Change-Id: I71e55e2d487fe561d3f596590b3e8102c5e921b5 Signed-off-by: Trishansh Bhardwaj <[email protected]> Signed-off-by: Francisco Franco <[email protected]>
franciscofranco · Sep 16, 2017 · d0eec9c · d0eec9c
1 parent 6a80416
commit d0eec9c
Showing 1 changed file with 1 addition and 3 deletions.
diff --git a/drivers/media/platform/msm/camera_v2/msm.c b/drivers/media/platform/msm/camera_v2/msm.c
@@ -780,11 +780,9 @@ static int msm_open(struct file *filep)
 	BUG_ON(!pvdev);
 
 	/* !!! only ONE open is allowed !!! */
-	if (atomic_read(&pvdev->opened))
+	if (atomic_cmpxchg(&pvdev->opened, 0, 1))
 		return -EBUSY;
 
-	atomic_set(&pvdev->opened, 1);
-
 	spin_lock_irqsave(&msm_pid_lock, flags);
 	msm_pid = get_pid(task_pid(current));
 	spin_unlock_irqrestore(&msm_pid_lock, flags);