udl-kms: change down_interruptible to down

BugLink: https://bugs.launchpad.net/bugs/1792392

commit 8456b99c upstream.

If we leave urbs around, it causes not only leak, but also memory
corruption. This patch fixes the function udl_free_urb_list, so that it
always waits for all urbs that are in progress.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/gpu/drm/udl/udl_main.c

@@ -141,18 +141,13 @@ static void udl_free_urb_list(struct drm_device *dev)
 	struct list_head *node;
 	struct urb_node *unode;
 	struct urb *urb;
-	int ret;
 	unsigned long flags;
 
 	DRM_DEBUG("Waiting for completes and freeing all render urbs\n");
 
 	/* keep waiting and freeing, until we've got 'em all */
 	while (count--) {
-
-		/* Getting interrupted means a leak, but ok at shutdown*/
-		ret = down_interruptible(&udl->urbs.limit_sem);
-		if (ret)
-			break;
+		down(&udl->urbs.limit_sem);
 
 		spin_lock_irqsave(&udl->urbs.lock, flags);