Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757346AbYKDRCu (ORCPT ); Tue, 4 Nov 2008 12:02:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755667AbYKDRCl (ORCPT ); Tue, 4 Nov 2008 12:02:41 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:47924 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755040AbYKDRCk (ORCPT ); Tue, 4 Nov 2008 12:02:40 -0500 From: "Rafael J. Wysocki" To: Mark Lord , Tejun Heo Subject: Re: [git patches] libata hibernation fixes Date: Tue, 4 Nov 2008 18:07:16 +0100 User-Agent: KMail/1.9.9 Cc: Linus Torvalds , Jeff Garzik , Andrew Morton , linux-ide@vger.kernel.org, LKML References: <20081104062734.GA4420@havoc.gtf.org> <200811041753.53342.rjw@sisk.pl> <49107F76.60107@rtr.ca> In-Reply-To: <49107F76.60107@rtr.ca> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200811041807.17183.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2759 Lines: 66 On Tuesday, 4 of November 2008, Mark Lord wrote: > Rafael J. Wysocki wrote: > > On Tuesday, 4 of November 2008, Linus Torvalds wrote: > >> On Tue, 4 Nov 2008, Jeff Garzik wrote: > >>> This adds code at a late stage (heading towards -rc4), but does > >>> eliminate a particular spin-up overcycling behavior associated with > >>> hibernation. > >> What does this have to do with hibernation? > >> > >> If it's a hibernation-only issue, then there is something wrong. > > > > No, it is not. On some machines it is a power-off issue, on the others it is > > hibernation and power-off issue. > > > >> Also, if it is an issue for normal power-off as well, then I wonder why > >> this isn't an issue on Windows. Does windows not spin down disks at all? > > > > In fact, AFAICS, it is an issue on Windows as well, at least if > > other-than-HP-preloaded version of Windows is used. > > > >> IOW, I really don't think this is correct. > >> > >> I _do_ think that correct might be: > >> > >> - maybe we just do something odd and different, triggering some BIOS > >> behavior that isn't there under Windows. > >> > >> So we should power down thigns differently so that the BIOS. > >> > >> - quite possibly: we just should not spin down disks at all, and just > >> flush them and do the "park" command thing. If we're _really_ powering > >> off, the disks will spin down on their own when power goes away. Maybe > >> that's what Windows does? > >> > >> So I really don't want to pull this, because I want to get more of an > >> explanation for why we need to do this at all. I also don't think this is > >> even appropriate at this stage in -rc. > >> > >> Is it a regression? If so, that just strengthens the questions above - > >> what did _we_ start doing wrong that this is needed at all? Let's just > >> stop doing that, not add some idiotic black-list for somethign that _we_ > >> do wrong. > > > > This is a regression, but from something like 2.6.25 or even earlier. > > I think what happened is we started to power-off disks at one point and these > > BIOS-es just don't like that. > > > > [Note that the issue only appears in _some_ HP boxes, other vendors don't > > seem to be affected at all.] > .. > > So, what happens if we just don't ever spin them down from the kernel? > Presumably they still spin-down normally (HP or otherwise) when the BIOS > actually cuts the power at the end of all of this? > > Just curious.. Well, I'll let Tejun answer that. :-) Thanks, Rafael -- 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/