Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752689Ab2EHJca (ORCPT ); Tue, 8 May 2012 05:32:30 -0400 Received: from lxorguk.ukuu.org.uk ([81.2.110.251]:34403 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751075Ab2EHJc3 (ORCPT ); Tue, 8 May 2012 05:32:29 -0400 Date: Tue, 8 May 2012 10:35:12 +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: <20120508103512.42db1c4b@pyramind.ukuu.org.uk> In-Reply-To: <4FA8557E.5080402@wwwdotorg.org> References: <4FA8557E.5080402@wwwdotorg.org> X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.8; x86_64-redhat-linux-gnu) Face: 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 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: 1021 Lines: 32 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); or if changing it for tty_hangup(tty) does it. There's some kind of lurking circular locking deadlock that I've not managed to trigger here but a couple of reports point towards. -- 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/