Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757113AbZIKWWS (ORCPT ); Fri, 11 Sep 2009 18:22:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756982AbZIKWWR (ORCPT ); Fri, 11 Sep 2009 18:22:17 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:39199 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751192AbZIKWWQ (ORCPT ); Fri, 11 Sep 2009 18:22:16 -0400 Date: Sat, 12 Sep 2009 00:21:54 +0200 From: Pavel Machek To: "Rafael J. Wysocki" Cc: OGAWA Hirofumi , Zdenek Kabelac , Christoph Hellwig , Linux Kernel Mailing List , linux-mmc@vger.kernel.org, viro@zeniv.linux.org.uk Subject: Re: Regression in suspend to ram in 2.6.31-rc kernels Message-ID: <20090911222154.GB11441@elf.ucw.cz> References: <20090910192354.GD23356@elf.ucw.cz> <87bplim1ce.fsf@devron.myhome.or.jp> <200909120004.02146.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200909120004.02146.rjw@sisk.pl> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2047 Lines: 49 On Sat 2009-09-12 00:04:02, Rafael J. Wysocki wrote: > On Friday 11 September 2009, OGAWA Hirofumi wrote: > > Pavel Machek writes: > > > > > On Wed 2009-09-09 22:21:56, OGAWA Hirofumi wrote: > > >> Pavel Machek writes: > > >> > > >> >> It seems > > >> >> > > >> >> 1) sync() (probabry "sync" command) > > >> >> 2) sync as part of suspend sequence > > >> >> 3) sync_filesystem() by mmc remove event > > >> >> > > >> >> I guess the root-cause of the problem would be 3). However, it would not > > >> >> be easy to fix, at least, we would need to think about what we want to > > >> >> do for it. So, to workaround it for now, I've made this patch. > > >> > > > >> > MMC driver trying to synchronize filesystems looks like ugly layering > > >> > violation to me. Why are we doing that? > > >> > > >> There is no _layering violation_ here. IIRC, mmc just tells card removed > > >> event to another layer (on some points of view, to tell event can be > > >> wrong though). The partition (block) layer does it by event. > > > > > > So what is the problem? Emulating sync when card is already removed > > > seems little ... interesting? > > > > Um..., sorry, I'm not sure what are you talking about. Of course, the > > problem of this is that system freeze on suspend. > > > > Or are you asking my guess of the cause, or something? If so, although > > I'm not reading all emails on this thread, from Zdenek's backtrace, the > > sequence would be > > > > 1) suspend mmc > > 2) mmc generates card removed event > > Which shouldn't happen. Are you sure? IIRC it depends on CONFIG_MMC_UNSAFE_RESUME. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- 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/