Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752927Ab0HQLcS (ORCPT ); Tue, 17 Aug 2010 07:32:18 -0400 Received: from mail-bw0-f46.google.com ([209.85.214.46]:40842 "EHLO mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750892Ab0HQLcQ (ORCPT ); Tue, 17 Aug 2010 07:32:16 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:x-enigmail-version:content-type :content-transfer-encoding; b=kmgimqJ9GKqEhduPjm4DPn4TRBl5QPivzML/Y880b/HCqzpFazZNyeP9o/ABALbx6s 1Sma77WuPfQg+DtFeRI0Yf0LV/iSwLIpkR21OQo0Egd0EWMiyHF15iqZEp/k4vfqh11/ fJ9LI9oNrQ6EPSjZ1ZlCiL35nq64PpVmxWg5A= Message-ID: <4C6A7281.3030804@gmail.com> Date: Tue, 17 Aug 2010 13:29:05 +0200 From: Tejun Heo User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.9.2.8) Gecko/20100802 Thunderbird/3.1.2 MIME-Version: 1.0 To: "Rafael J. Wysocki" CC: Stephan Diestelhorst , "linux-kernel@vger.kernel.org" , "linux-ide@vger.kernel.org" , "linux-pm@lists.osdl.org" , Stephan Diestelhorst Subject: Re: [PATCH] SATA / AHCI: Do not play with the link PM during suspend to RAM References: <201007091750.05020.stephan.diestelhorst@amd.com> <201008171132.56431.stephan.diestelhorst@amd.com> <4C6A6145.7020707@gmail.com> <201008171319.25080.rjw@sisk.pl> In-Reply-To: <201008171319.25080.rjw@sisk.pl> X-Enigmail-Version: 1.1.1 Content-Type: text/plain; charset=ISO-8859-2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1410 Lines: 34 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. Stranger things have happened in the ATA la-la land. :-) Also, it makes non-lpm and lpm cases leave the controller and device in different states when it goes to sleep, which _really_ bothers me. Combined with the timing dependent nature of DIPM, I worry this might lead to very obscure issues and would much prefer to make sure everything is in fixed, known, fully powered state before committing to any major operations. I might be paranoid tho. I'll think more about it. > 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? Thanks. -- tejun -- 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/