From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg Kroah-Hartman Subject: Re: Regression due to d29f3ef "tty_lock: Localise the lock" Date: Tue, 8 May 2012 09:09:30 -0700 Message-ID: <20120508160930.GB20433@kroah.com> References: <4FA8557E.5080402@wwwdotorg.org> <20120508103512.42db1c4b@pyramind.ukuu.org.uk> <4FA93FEB.2060200@wwwdotorg.org> <20120508170442.409ccbe4@bob.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20120508170442.409ccbe4-Z/y2cZnRghHXmaaqVzeoHQ@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Alan Cox Cc: Stephen Warren , Alan Cox , Arnd Bergmann , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-tegra@vger.kernel.org On Tue, May 08, 2012 at 05:04:42PM +0100, Alan Cox wrote: > On Tue, 08 May 2012 09:46:51 -0600 > Stephen Warren wrote: > > > On 05/08/2012 03:35 AM, Alan Cox wrote: > > > On Mon, 07 May 2012 17:06:38 -0600 > > > Stephen Warren wrote: > > > > > >> Alan, > > >> > > >> Commit d29f3ef "tty_lock: Localise the lock" appears to cause a > > >> problem for me. > > >> > > >> With this commit (as in next-20120507), I can no longer log into my > > >> system (NVIDIA Tegra device with ARM CPU) over the serial console, > > >> since the login prompt no longer appears. If I wait a few minutes, > > >> I see the following console spew: > > > > > > Eep. If it's reproducable can you test whether adding the > > > unlock/relock in drivers/tty/pty.c does the trick ? > > > > > > ie: > > > tty_unlock(tty); > > > tty_vhangup(tty); > > > tty_lock(tty); > > > > Yes, that change in pty_close() solves the problem. > > Ok Greg - I think we should go with putting that unlock back until we > understand exactly what is going on. Ok, care to send a patch that does this so I get it correct, and we get a reported-by from Stephen? thanks, greg k-h