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Diffstat (limited to 'drivers/media/video/pms.c')
-rw-r--r--drivers/media/video/pms.c22
1 files changed, 20 insertions, 2 deletions
diff --git a/drivers/media/video/pms.c b/drivers/media/video/pms.c
index 7c84f795db54..b39794f0baf5 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,