Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758695AbYGAOi3 (ORCPT ); Tue, 1 Jul 2008 10:38:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755866AbYGAOiV (ORCPT ); Tue, 1 Jul 2008 10:38:21 -0400 Received: from saeurebad.de ([85.214.36.134]:55287 "EHLO saeurebad.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754481AbYGAOiU (ORCPT ); Tue, 1 Jul 2008 10:38:20 -0400 From: Johannes Weiner To: Takashi Iwai Cc: Mathieu Chouquet-Stringer , Jaroslav Kysela , linux-kernel@vger.kernel.org Subject: Re: Longstanding bug in ac97/intel8x0 resume/init References: <87hcca3xkx.fsf@saeurebad.de> <8763rsa5qk.fsf@skyscraper.fehenstaub.lan> Date: Tue, 01 Jul 2008 16:37:42 +0200 In-Reply-To: (Takashi Iwai's message of "Tue, 01 Jul 2008 15:43:56 +0200") Message-ID: <87k5g54qmh.fsf@skyscraper.fehenstaub.lan> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.0.60 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.1.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1804 Lines: 46 Hi, Takashi Iwai writes: > At 30 Jun 2008 20:58:03 +0200, > Mathieu Chouquet-Stringer wrote: >> >> Hey there, >> >> hannes@saeurebad.de (Johannes Weiner) writes: >> > Johannes Weiner writes: >> > > my laptop has muted sound after resuming the soundcard (by >> > > s2ram/hibernation). The problem seems to be that the cached register >> > > values are not written back to the device properly. >> >> I've got the same exact issue on a Thinkpad T30: >> >> 0 [I82801CAICH3 ]: ICH - Intel 82801CA-ICH3 >> Intel 82801CA-ICH3 with AD1881A at irq 5 >> >> 00:1f.5 Multimedia audio controller: Intel Corporation 82801CA/CAM AC'97 Audio Controller (rev 02) > > Does this happen for both hibernation and S2RAM? > And, resetting the mixer repairs the mute state, right? > If yes, the problem appears independently from the codec chip. Hmm... Yes, happens in both cases here. The alsamixer shows the state of the channels before the suspension(!). If I change the channel state, the sound works again. No complete reset needed at all, I just have to increase/decrease the value a bit (for each affected channel). >From my experiments with the code, I figured that the cached register values are not written back properly on resume. The cache is in the correct state but the hardware is not. This also explains the behaviour when changing the channels with alsamixer; the register cache is touched and written back (and this time, the value really gets through to the hardware). Hannes -- 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/