[media] em28xx: fix race on disconnect
This patch closes the race on the device and extension lists at USB disconnect
time. Previously, the device was removed from the device list during
em28xx_release_resources(), and then passed to the em28xx_close_extension()
function so that all extensions could run their fini() operations. However, this
left a (brief, theoretical, highly unlikely ;-)) window between these two calls
during which a new module could call em28xx_register_extension(). The result
would have been that the em28xx_usb_disconnect() function would also have passed
the device to the new extension's fini() function, despite never having called
the extension's init() function.
This patch also restores em28xx_close_extension()'s symmetry with
em28xx_init_extension(), and establishes the property that every device in the
device list must have been initialised for every extension in the extension list.
Signed-off-by: Chris Rankin <rankincj@yahoo.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/em28xx/em28xx-cards.c b/drivers/media/video/em28xx/em28xx-cards.c
index 7425f92..7297d90 100644
--- a/drivers/media/video/em28xx/em28xx-cards.c
+++ b/drivers/media/video/em28xx/em28xx-cards.c
@@ -2800,9 +2800,9 @@
#endif /* CONFIG_MODULES */
/*
- * em28xx_realease_resources()
+ * em28xx_release_resources()
* unregisters the v4l2,i2c and usb devices
- * called when the device gets disconected or at module unload
+ * called when the device gets disconnected or at module unload
*/
void em28xx_release_resources(struct em28xx *dev)
{
@@ -2816,8 +2816,6 @@
em28xx_release_analog_resources(dev);
- em28xx_remove_from_devlist(dev);
-
em28xx_i2c_unregister(dev);
v4l2_device_unregister(&dev->v4l2_dev);
@@ -3255,7 +3253,7 @@
/*
* em28xx_usb_disconnect()
- * called when the device gets diconencted
+ * called when the device gets disconnected
* video device will be unregistered on v4l2_close in case it is still open
*/
static void em28xx_usb_disconnect(struct usb_interface *interface)