Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756564Ab2EHPt3 (ORCPT ); Tue, 8 May 2012 11:49:29 -0400 Received: from mga11.intel.com ([192.55.52.93]:32047 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756514Ab2EHPt1 (ORCPT ); Tue, 8 May 2012 11:49:27 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="150566526" Date: Tue, 8 May 2012 17:04:42 +0100 From: Alan Cox To: Stephen Warren Cc: Alan Cox , Greg Kroah-Hartman , Arnd Bergmann , "linux-kernel@vger.kernel.org" , "linux-tegra@vger.kernel.org" Subject: Re: Regression due to d29f3ef "tty_lock: Localise the lock" Message-ID: <20120508170442.409ccbe4@bob.linux.org.uk> In-Reply-To: <4FA93FEB.2060200@wwwdotorg.org> References: <4FA8557E.5080402@wwwdotorg.org> <20120508103512.42db1c4b@pyramind.ukuu.org.uk> <4FA93FEB.2060200@wwwdotorg.org> Organization: Intel X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.8; x86_64-redhat-linux-gnu) Organisation: Intel Corporation UK Ltd, registered no. 1134945 (England), Registered office Pipers Way, Swindon, SN3 1RJ Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1202 Lines: 36 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. Alan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/