On 05/07/2012 07:00 PM, Sasha Levin wrote:

quoted

So whatever your trace is showing, that's not the bug. Something more
complicated would appear to be afoot.

Oddly enough, tty != tty->link, but the lockdep warning triggers.

Any idea why it might happen?

I think so, both locks are the same lockdep class. So lockdep thinks it
is the same lock. However this is a false positive. I guess we need
mutex_lock_nested...

regards,
-- 
js
suse labs