v4l: move BKL down to the driver level.

From: Hans Verkuil <hverkuil@xs4all.nl>

The BKL is now moved from the video_open function in v4l2-dev.c to the
various drivers. It seems about a third of the drivers already has a
lock of some sort protecting the open(), another third uses
video_exclusive_open (yuck!) and the last third required adding the
BKL in their open function.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>

1 files changed, 6 insertions, 0 deletions

diff --git a/linux/drivers/media/video/usbvideo/vicam.c b/linux/drivers/media/video/usbvideo/vicam.c
index e31b64f17..e7330fe4f 100644
--- a/linux/drivers/media/video/usbvideo/vicam.c
+++ b/linux/drivers/media/video/usbvideo/vicam.c
@@ -798,20 +798,24 @@ vicam_open(struct inode *inode, struct file *file)
 	 * rely on this fact forever.
 	 */
 
+	lock_kernel();
 	if (cam->open_count > 0) {
 		printk(KERN_INFO
 		       "vicam_open called on already opened camera");
+		unlock_kernel();
 		return -EBUSY;
 	}
 
 	cam->raw_image = kmalloc(VICAM_MAX_READ_SIZE, GFP_KERNEL);
 	if (!cam->raw_image) {
+		unlock_kernel();
 		return -ENOMEM;
 	}
 
 	cam->framebuf = rvmalloc(VICAM_MAX_FRAME_SIZE * VICAM_FRAMES);
 	if (!cam->framebuf) {
 		kfree(cam->raw_image);
+		unlock_kernel();
 		return -ENOMEM;
 	}
 
@@ -819,6 +823,7 @@ vicam_open(struct inode *inode, struct file *file)
 	if (!cam->cntrlbuf) {
 		kfree(cam->raw_image);
 		rvfree(cam->framebuf, VICAM_MAX_FRAME_SIZE * VICAM_FRAMES);
+		unlock_kernel();
 		return -ENOMEM;
 	}
 
@@ -836,6 +841,7 @@ vicam_open(struct inode *inode, struct file *file)
 	cam->open_count++;
 
 	file->private_data = cam;
+	unlock_kernel();
 
 	return 0;
 }