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, 3 insertions, 0 deletions

diff --git a/linux/drivers/media/video/saa7134/saa7134-empress.c b/linux/drivers/media/video/saa7134/saa7134-empress.c
index 45bd752a9..a454968f7 100644
--- a/linux/drivers/media/video/saa7134/saa7134-empress.c
+++ b/linux/drivers/media/video/saa7134/saa7134-empress.c
@@ -79,9 +79,11 @@ static int ts_open(struct inode *inode, struct file *file)
 	struct saa7134_dev *dev;
 	int err;
 
+	lock_kernel();
 	list_for_each_entry(dev, &saa7134_devlist, devlist)
 		if (dev->empress_dev && dev->empress_dev->minor == minor)
 			goto found;
+	unlock_kernel();
 	return -ENODEV;
  found:
 
@@ -103,6 +105,7 @@ static int ts_open(struct inode *inode, struct file *file)
 done_up:
 	mutex_unlock(&dev->empress_tsq.vb_lock);
 done:
+	unlock_kernel();
 	return err;
 }