1 files changed, 21 insertions, 2 deletions

diff --git a/drivers/media/video/pms.c b/drivers/media/video/pms.c
index 7c84f795db54..994807818aa2 100644
--- a/drivers/media/video/pms.c
+++ b/drivers/media/video/pms.c
@@ -47,6 +47,7 @@ struct pms_device
         struct video_picture picture;
         int height;
         int width;
+        unsigned long in_use;
         struct mutex lock;
 };
 
@@ -881,10 +882,27 @@ static ssize_t pms_read(struct file *file, char __user *buf,
         return len;
 }
 
+static int pms_exclusive_open(struct inode *inode, struct file *file)
+{
+        struct video_device *v = video_devdata(file);
+        struct pms_device *pd = (struct pms_device *)v;
+
+        return test_and_set_bit(0, &pd->in_use) ? -EBUSY : 0;
+}
+
+static int pms_exclusive_release(struct inode *inode, struct file *file)
+{
+        struct video_device *v = video_devdata(file);
+        struct pms_device *pd = (struct pms_device *)v;
+
+        clear_bit(0, &pd->in_use);
+        return 0;
+}
+
 static const struct file_operations pms_fops = {
         .owner          = THIS_MODULE,
-        .open           = video_exclusive_open,
-        .release        = video_exclusive_release,
+        .open           = pms_exclusive_open,
+        .release        = pms_exclusive_release,
         .ioctl          = pms_ioctl,
 #ifdef CONFIG_COMPAT
         .compat_ioctl   = v4l_compat_ioctl32,
@@ -897,6 +915,7 @@ static struct video_device pms_template=
 {
         .name           = "Mediavision PMS",
         .fops           = &pms_fops,
+        .release        = video_device_release_empty,
 };
 
 static struct pms_device pms_device;