From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932370Ab0IGRiC (ORCPT ); Tue, 7 Sep 2010 13:38:02 -0400 Received: from mga09.intel.com ([134.134.136.24]:20534 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932267Ab0IGRh7 (ORCPT ); Tue, 7 Sep 2010 13:37:59 -0400 Message-Id: <8u3s94$geonkf@orsmga002.jf.intel.com> X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.56,329,1280732400"; d="scan'208";a="552361627" Date: Tue, 07 Sep 2010 18:37:55 +0100 To: Eric Anholt , Andy Isaacson , linux-kernel@vger.kernel.org Subject: Re: [2.6.36-rc2 regression] X201s: resume-from-S2R hangs Cc: Zou Nan hai References: <20100906090536.GA12250@hexapodia.org> <87fwxlbhq5.fsf@pollan.anholt.net> From: Chris Wilson In-Reply-To: <87fwxlbhq5.fsf@pollan.anholt.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 07 Sep 2010 10:12:34 -0700, Eric Anholt wrote: > On Mon, 6 Sep 2010 02:05:36 -0700, Andy Isaacson wrote: > > I have a Thinkpad X201s on which suspend-to-RAM was quite reliable until > > after 2.6.36-rc1; with problematic kernels, suspend seems to work OK > > (the machine goes to sleep with the moon LED steadily lit) but on resume > > the LCD never lights up (and it's not just the backlight, the screen > > isn't drawing at all) and the keyboard and network are dead. Nothing > > makes it to syslog, either. The moon LED is turned off though. > > > > There seems to be some timing component to the problem -- some problem > > kernels will suspend reliably 25% or 50% of the time and hang the rest. > > There also seems to be some per-reboot state involved; one problem > > kernel suspended successfully and survived 25 suspends in a row without > > triggering a failure. (But after a reboot, the first suspend hung...) > > Other problem kernels fail on 4 out of 4 reboots. We introduced a timing regression which should be fixed by http://cgit.freedesktop.org/~ickle/drm-intel/ drm-intel-fixes [http://cgit.freedesktop.org/~ickle/drm-intel/commit/?id=300387c0b57d75e5218e2881d6ad2720657a8bcf] > > Bisecting is pretty hard under these conditions, but it seems to point > > to > > Weird. That's exactly the hardware that I tested RC6 on, and I haven't > seen a single resume failure on mine. Sounds like time to revert for > this release. At the moment we have a second resume regression that has been difficult to reproduce, https://bugs.freedesktop.org/show_bug.cgi?id=29406 : commit d1b851fc0d105caa6b6e3e7c92d2987dfb52cbe0 Author: Zou Nan hai Date: Fri May 21 09:08:57 2010 +0800 drm/i915: implement BSD ring buffer V2 The workaround for this is to #define HAS_BSD(dev) 0 [i915_drv.h]. Andy, can you try the workaround to see if this is the same issue in a different guise? Alternatively, we can be optimistic that it is just a timing issue fixed in drm-intel-next. :) Otherwise we will revert that patch. Thanks. -Chris -- Chris Wilson, Intel Open Source Technology Centre