Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755682Ab0HQMKe (ORCPT ); Tue, 17 Aug 2010 08:10:34 -0400 Received: from tx2ehsobe002.messaging.microsoft.com ([65.55.88.12]:51029 "EHLO TX2EHSOBE004.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751379Ab0HQMKc (ORCPT ); Tue, 17 Aug 2010 08:10:32 -0400 X-SpamScore: -38 X-BigFish: VPS-38(zzbb2dK1432N9370J98dN4015L9371Pzz1202hzz15d4Rz32i2a8h61h) X-Spam-TCS-SCL: 0:0 X-WSS-ID: 0L7APT8-02-K64-02 X-M-MSG: From: Stephan Diestelhorst Organization: AMD OSRC To: Tejun Heo Subject: Re: [PATCH] SATA / AHCI: Do not play with the link PM during suspend to RAM Date: Tue, 17 Aug 2010 14:10:20 +0200 User-Agent: KMail/1.13.5 (Linux/2.6.34-pm-link-fix; KDE/4.5.0; x86_64; ; ) CC: "Rafael J. Wysocki" , "linux-kernel@vger.kernel.org" , "linux-ide@vger.kernel.org" , "linux-pm@lists.osdl.org" , Stephan Diestelhorst References: <201007091750.05020.stephan.diestelhorst@amd.com> <201008171319.25080.rjw@sisk.pl> <4C6A7281.3030804@gmail.com> In-Reply-To: <4C6A7281.3030804@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-2" Content-Transfer-Encoding: 7bit Message-ID: <201008171410.21382.stephan.diestelhorst@amd.com> X-Reverse-DNS: ausb3extmailp02.amd.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1525 Lines: 38 Hi, On Tuesday 17 August 2010, 13:29:05 Tejun Heo wrote: > Hello, > > On 08/17/2010 01:19 PM, Rafael J. Wysocki wrote: > > Well, I wonder what the real reason for doing the link power management > > thing at this particular point in the suspend code path is. It just seems to > > disable the link power management, but then the controller is put into a > > low-power state and is reset from scratch during resume, so I'm not quite > > sure how skipping that code could possibly lead to any problems. > > > Perhaps we could move the link PM manipulation to the prepare stage > > of suspend? > > Yeah, one possibility is that the devices misbehave if they receive > LPM commands while suspended. Does commenting out sd_suspend resolve > the issue too? If you want me to test anything... let me know. Since I do not know much about the ATA code, I do not know what to change where. (A simple grep for sd_suspend in drivers/ata didn't turn up anything.) Thanks, Stephan -- Stephan Diestelhorst, AMD Operating System Research Center stephan.diestelhorst@amd.com, Tel. +49 (0)351 448 356 719 Advanced Micro Devices GmbH Einsteinring 24 85609 Dornach General Managers: Alberto Bozzo, Andrew Bowd Registration: Dornach, Landkr. Muenchen; Registerger. Muenchen, HRB Nr. 43632 -- 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/