[media] au0828: fix disconnect sequence

The driver crashed when the device was disconnected while an application
still had a device node open. Fixed by using the release() callback of struct
v4l2_device.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/usb/au0828/au0828-core.c

@@ -125,36 +125,48 @@ static int recv_control_msg(struct au0828_dev *dev, u16 request, u32 value,
 	return status;
 }
 
-static void au0828_usb_disconnect(struct usb_interface *interface)
+static void au0828_usb_release(struct au0828_dev *dev)
 {
-	struct au0828_dev *dev = usb_get_intfdata(interface);
-
-	dprintk(1, "%s()\n", __func__);
-
-	/* Digital TV */
-	au0828_dvb_unregister(dev);
-
-#ifdef CONFIG_VIDEO_AU0828_V4L2
-	if (AUVI_INPUT(0).type != AU0828_VMUX_UNDEFINED)
-		au0828_analog_unregister(dev);
-#endif
-
 	/* I2C */
 	au0828_i2c_unregister(dev);
 
+	kfree(dev);
+}
+
 #ifdef CONFIG_VIDEO_AU0828_V4L2
+static void au0828_usb_v4l2_release(struct v4l2_device *v4l2_dev)
+{
+	struct au0828_dev *dev =
+		container_of(v4l2_dev, struct au0828_dev, v4l2_dev);
+
 	v4l2_ctrl_handler_free(&dev->v4l2_ctrl_hdl);
 	v4l2_device_unregister(&dev->v4l2_dev);
+	au0828_usb_release(dev);
+}
 #endif
 
-	usb_set_intfdata(interface, NULL);
+static void au0828_usb_disconnect(struct usb_interface *interface)
+{
+	struct au0828_dev *dev = usb_get_intfdata(interface);
+
+	dprintk(1, "%s()\n", __func__);
+
+	/* Digital TV */
+	au0828_dvb_unregister(dev);
 
+	usb_set_intfdata(interface, NULL);
 	mutex_lock(&dev->mutex);
 	dev->usbdev = NULL;
 	mutex_unlock(&dev->mutex);
-
-	kfree(dev);
-
+#ifdef CONFIG_VIDEO_AU0828_V4L2
+	if (AUVI_INPUT(0).type != AU0828_VMUX_UNDEFINED) {
+		au0828_analog_unregister(dev);
+		v4l2_device_disconnect(&dev->v4l2_dev);
+		v4l2_device_put(&dev->v4l2_dev);
+		return;
+	}
+#endif
+	au0828_usb_release(dev);
 }
 
 static int au0828_usb_probe(struct usb_interface *interface,
@@ -203,6 +215,8 @@ static int au0828_usb_probe(struct usb_interface *interface,
 	dev->boardnr = id->driver_info;
 
 #ifdef CONFIG_VIDEO_AU0828_V4L2
+	dev->v4l2_dev.release = au0828_usb_v4l2_release;
+
 	/* Create the v4l2_device */
 	retval = v4l2_device_register(&interface->dev, &dev->v4l2_dev);
 	if (retval) {

drivers/media/usb/au0828/au0828-video.c

@@ -1063,14 +1063,7 @@ static int au0828_v4l2_close(struct file *filp)
 		res_free(fh, AU0828_RESOURCE_VBI);
 	}
 
-	if (dev->users == 1) {
-		if (dev->dev_state & DEV_DISCONNECTED) {
-			au0828_analog_unregister(dev);
-			kfree(fh);
-			kfree(dev);
-			return 0;
-		}
-
+	if (dev->users == 1 && video_is_registered(video_devdata(filp))) {
 		au0828_analog_stream_disable(dev);
 
 		au0828_uninit_isoc(dev);