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: Wed, 18 Aug 2010 08:12:24 +0200 Message-ID: <4C6B79C8.7080602@gmail.com> References: <201007091750.05020.stephan.diestelhorst@amd.com> <4C6A6145.7020707@gmail.com> <201008171229.28917.stephan.diestelhorst@amd.com> <201008171251.29441.stephan.diestelhorst@amd.com> <4C6AA50F.3090801@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-bw0-f46.google.com ([209.85.214.46]:41610 "EHLO mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751105Ab0HRGL6 (ORCPT ); Wed, 18 Aug 2010 02:11:58 -0400 In-Reply-To: Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Stephan Diestelhorst Cc: "Rafael J. Wysocki" , "linux-kernel@vger.kernel.org" , "linux-ide@vger.kernel.org" , "linux-pm@lists.osdl.org" , stephan.diestelhorst@amd.com Hello, On 08/17/2010 11:28 PM, Stephan Diestelhorst wrote: > 2010/8/17 Tejun Heo : >> On 08/17/2010 12:51 PM, Stephan Diestelhorst wrote: >>> I *think* I have applied the patch correctly. Please find a copy of >>> "git show" in the build directory attached. This should be the right >>> thing, shouldn't it? >> >>> Maybe I forgot to speify a particular debug option / verbosity? >> >>> I've also confirmed that the "XXX ahci_set_ipm" is present in >>> libahci.ko. So either I've screwed up badly when compiling the initrd, >>> the code is not executed or the printout does not make it into any >>> logfile anymore. >> >> Yeah, that's weird. You're enabling IPM, right? > > Erm... Honestly, I have no clue. What is IPM? How do I enable it? This is a > Kubuntu Lucid 10.04 distribution, and I have not touched too much. In > particular, the kernels have been from upstream git, just with the Ubuntu config > copied over. > > Maybe it is just not enabled? I am guessing that IPM might be IDE power > management? Or intelligent, integrated? Google turns up this email thread > as one of the first hits and nothing else conclusive. It's interface power management, also called link power management. You can check whether it's enabled by $ cat /sys/class/scsi_host/host0/link_power_management_policy If it says max_performance, it's disabled. If it says anything else, it's enabled. Thanks. -- tejun