From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756652Ab3HLNjI (ORCPT ); Mon, 12 Aug 2013 09:39:08 -0400 Received: from mailout39.mail01.mtsvc.net ([216.70.64.83]:52613 "EHLO n12.mail01.mtsvc.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756181Ab3HLNjE (ORCPT ); Mon, 12 Aug 2013 09:39:04 -0400 Message-ID: <5208E575.1080008@hurleysoftware.com> Date: Mon, 12 Aug 2013 09:39:01 -0400 From: Peter Hurley User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130803 Thunderbird/17.0.8 MIME-Version: 1.0 To: Sergey Senozhatsky , Greg Kroah-Hartman CC: linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, Jiri Slaby , Belisko Marek Subject: Re: [PATCH tty-next] n_tty: Fix termios_rwsem lockdep false positive References: <20130731114726.GA11570@cpv436-motbuntu.spb.ea.mot-mobility.com> <1376222663-5666-1-git-send-email-peter@hurleysoftware.com> <20130812092810.GA26400@cpv436-motbuntu.spb.ea.mot-mobility.com> <20130812105041.GA2268@swordfish> <5208DB32.40304@hurleysoftware.com> <20130812131949.GA2297@swordfish> In-Reply-To: <20130812131949.GA2297@swordfish> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated-User: 990527 peter@hurleysoftware.com X-MT-INTERNAL-ID: 8fa290c2a27252aacf65dbc4a42f3ce3735fb2a4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/12/2013 09:19 AM, Sergey Senozhatsky wrote: > On (08/12/13 08:55), Peter Hurley wrote: >>>>> [..] >>>>> drivers/tty/n_tty.c | 25 +++++++++++-------------- >>>>> 1 file changed, 11 insertions(+), 14 deletions(-) >>>>> >>> >>> I hate to do this, but isn't it actually my patch posted here >>> https://lkml.org/lkml/2013/8/1/510 >>> >>> which was tagged as `wrong'? >> >> Sergey, >> >> My apologies; I was mistaken regarding this problem being a lockdep >> regression (although it's still a false positive from lockdep). Once >> I had worked around some issues with the nouveau driver, I was able to >> reproduce the lockdep report on 3.10. >> > no problem. > >> I included Artem's lockdep report in the changelog because I received >> that first, on 30 July. >> >> My patch below is not the same as your patch of 1 Aug. This patch >> preserves the protected access of termios.c_cc[VMIN] and termios.c_cc[VTIME] >> (via the MIN_CHAR() and TIME_CHAR() macros). > > fair enough. v3 was protecting VMIN/VTIME (my bad, I noticed this a bit later), > but I didn't submit it since v2 did not get positive response. > >> If you'd prefer, I could add to changelog: >> >> Patch based on original posted here https://lkml.org/lkml/2013/8/1/510 >> by Sergey Senozhatsky > > if you don't mind, that would be great. Ok. Greg, Should I re-spin a v2 to include the note above (or can you add it with Artem's Tested-by)? Regards, Peter Hurley