Am Donnerstag, 12. Januar 2012, 10:42:22 schrieb Ming Lei:

There is no reason to hold hiddev->existancelock before
calling usb_deregister_dev, so move it out of the lock.

The patch fixes the lockdep warning below [1].

[1], lockdep warning

Hi,

you should however hold the lock while you unset hiddev->exist
and you should unset hiddev->exist before you call usb_deregister_dev().
So the diagnosis is very good, but the patch needs a bit elaboration.

	Regards
		Oliver