diff -Nur linux-2.6.38/drivers/media/dvb/dvb-core/dvbdev.c linux-2.6.38/drivers/media/dvb/dvb-core/dvbdev.c
--- linux-2.6.38/drivers/media/dvb/dvb-core/dvbdev.c
+++ linux-2.6.38/drivers/media/dvb/dvb-core/dvbdev.c
@@ -83,8 +83,11 @@ static int dvb_device_open(struct inode *inode, struct file *file)
 			file->f_op = old_fops;
 			goto fail;
 		}
-		if(file->f_op->open)
+		if(file->f_op->open) {
+			mutex_unlock(&dvbdev_mutex);
 			err = file->f_op->open(inode,file);
+			mutex_lock(&dvbdev_mutex);
+		}
 		if (err) {
 			fops_put(file->f_op);
 			file->f_op = fops_get(old_fops);
--