Re: [PATCH 0/2] Provide a driver for the Apple Magic Mouse - opps

From: Jiri Kosina
Date: Tue Feb 16 2010 - 07:55:35 EST


On Tue, 16 Feb 2010, Ed Tomlinson wrote:

> > Almost... you need to do hid_hw_stop() first and only then unregister
> > input device, Otherwise if you unload the module while moving the mouse
> > it is likely to still oops.
>
> The exit routing for the module also has a hid_hw_stop. Is it going to cause
> problems when it gets called twice?

The routine wasn't probably meant/designed with re-entrancy in mind, but
looking quickly at all the subsequent callpaths, I don't see why it should
cause any problem, as skb_queue_purge(), usb_kill_urb() and usb_free_urb()
should be safe.

Maybe we should even add test_bit() for HID_STARTED and HID_DISCONNECTED
at the beginning of the low-level drivers' ->stop callbacks, so that we
don't do all the magic when all the work has been already done.

--
Jiri Kosina
SUSE Labs, Novell Inc.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/