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, 16 insertions, 4 deletions

diff --git a/linux/drivers/media/video/bt8xx/bttv-driver.c b/linux/drivers/media/video/bt8xx/bttv-driver.c
index 40f8a0332..d5cb13e40 100644
--- a/linux/drivers/media/video/bt8xx/bttv-driver.c
+++ b/linux/drivers/media/video/bt8xx/bttv-driver.c
@@ -3248,6 +3248,7 @@ static int bttv_open(struct inode *inode, struct file *file)
 
 	dprintk(KERN_DEBUG "bttv: open minor=%d\n",minor);
 
+	lock_kernel();
 	for (i = 0; i < bttv_num; i++) {
 		if (bttvs[i].video_dev &&
 		    bttvs[i].video_dev->minor == minor) {
@@ -3262,16 +3263,20 @@ static int bttv_open(struct inode *inode, struct file *file)
 			break;
 		}
 	}
-	if (NULL == btv)
+	if (NULL == btv) {
+		unlock_kernel();
 		return -ENODEV;
+	}
 
 	dprintk(KERN_DEBUG "bttv%d: open called (type=%s)\n",
 		btv->c.nr,v4l2_type_names[type]);
 
 	/* allocate per filehandle data */
 	fh = kmalloc(sizeof(*fh),GFP_KERNEL);
-	if (NULL == fh)
+	if (NULL == fh) {
+		unlock_kernel();
 		return -ENOMEM;
+	}
 	file->private_data = fh;
 	*fh = btv->init;
 	fh->type = type;
@@ -3311,6 +3316,7 @@ static int bttv_open(struct inode *inode, struct file *file)
 	bttv_vbi_fmt_reset(&fh->vbi_fmt, btv->tvnorm);
 
 	bttv_field_count(btv);
+	unlock_kernel();
 	return 0;
 }
 
@@ -3451,21 +3457,26 @@ static int radio_open(struct inode *inode, struct file *file)
 
 	dprintk("bttv: open minor=%d\n",minor);
 
+	lock_kernel();
 	for (i = 0; i < bttv_num; i++) {
 		if (bttvs[i].radio_dev->minor == minor) {
 			btv = &bttvs[i];
 			break;
 		}
 	}
-	if (NULL == btv)
+	if (NULL == btv) {
+		unlock_kernel();
 		return -ENODEV;
+	}
 
 	dprintk("bttv%d: open called (radio)\n",btv->c.nr);
 
 	/* allocate per filehandle data */
 	fh = kmalloc(sizeof(*fh), GFP_KERNEL);
-	if (NULL == fh)
+	if (NULL == fh) {
+		unlock_kernel();
 		return -ENOMEM;
+	}
 	file->private_data = fh;
 	*fh = btv->init;
 	v4l2_prio_open(&btv->prio, &fh->prio);
@@ -3478,6 +3489,7 @@ static int radio_open(struct inode *inode, struct file *file)
 	audio_input(btv,TVAUDIO_INPUT_RADIO);
 
 	mutex_unlock(&btv->lock);
+	unlock_kernel();
 	return 0;
 }