media: Fix media device minor registration

commit 8c89ddd536bbe97c1e50424778a139abbf5763c3 upstream.

The find_next_zero_bit() is called with the from and to arguments in the
wrong order. This results in the function always returning 0, and all
media devices being registered with minor 0. Furthermore, mdev->minor is
then used before being assigned with the find_next_zero_bit() return
value. This really makes sure we'll always use minor 0.

Fix this and let the system support more than one media device.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/media/media-devnode.c b/drivers/media/media-devnode.c
index af5263c6625adeafab44bfa5cdff167122ff52d5..7b42ace419d9378c32407650044b2daa69adc0a6 100644 (file)
--- a/drivers/media/media-devnode.c
+++ b/drivers/media/media-devnode.c
@@ -213,14 +213,14 @@ int __must_check media_devnode_register(struct media_devnode *mdev)
 
        /* Part 1: Find a free minor number */
        mutex_lock(&media_devnode_lock);
-       minor = find_next_zero_bit(media_devnode_nums, 0, MEDIA_NUM_DEVICES);
+       minor = find_next_zero_bit(media_devnode_nums, MEDIA_NUM_DEVICES, 0);
        if (minor == MEDIA_NUM_DEVICES) {
                mutex_unlock(&media_devnode_lock);
                printk(KERN_ERR "could not get a free minor\n");
                return -ENFILE;
        }
 
-       set_bit(mdev->minor, media_devnode_nums);
+       set_bit(minor, media_devnode_nums);
        mutex_unlock(&media_devnode_lock);
 
        mdev->minor = minor;