From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH] SATA / AHCI: Do not play with the link PM during suspend to RAM Date: Thu, 02 Sep 2010 11:06:57 +0200 Message-ID: <4C7F6931.4050707@gmail.com> References: <201007091750.05020.stephan.diestelhorst@amd.com> <4C7376BE.5040006@gmail.com> <201008242239.43249.rjw@sisk.pl> <201008270109.36687.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-fx0-f46.google.com ([209.85.161.46]:46655 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750830Ab0IBJHE (ORCPT ); Thu, 2 Sep 2010 05:07:04 -0400 In-Reply-To: <201008270109.36687.rjw@sisk.pl> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: "Rafael J. Wysocki" Cc: Stephan Diestelhorst , "linux-kernel@vger.kernel.org" , "linux-ide@vger.kernel.org" , "linux-pm@lists.osdl.org" , Stephan Diestelhorst Hello, Rafael. On 08/27/2010 01:09 AM, Rafael J. Wysocki wrote: > Well, no luck. I was able to reproduce the issue on my box with this patch > applied on top of 2.6.32-rc2. > > Which probably means that the link power management is not really involved > here and seems to turn up this statement: > > rc = ata_host_request_pm(host, mesg, 0, ATA_EHI_QUIET, 1); > > in ata_host_suspend() as the culprit. > > Does it make sense? So, LPM doesn't have anything to do with the problem. The fact that this only happens on specific machines is strange. Maybe the BIOS is doing something fishy to the controller on disk spindown during suspend. Can the BIOS tell that the system is going for suspend by the time sd suspend is called? I'll prep another patch which will make EH skip certain steps and ignore failures during suspend, which basically mimics what your patch does but in safer way. Thanks. -- tejun