Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752930Ab0BAKWx (ORCPT ); Mon, 1 Feb 2010 05:22:53 -0500 Received: from nat.nue.novell.com ([195.135.221.3]:48416 "EHLO emea5-mh.id5.novell.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751011Ab0BAKWv (ORCPT ); Mon, 1 Feb 2010 05:22:51 -0500 Message-ID: <4B66AB7F.7050908@suse.de> Date: Mon, 01 Feb 2010 13:22:55 +0300 From: Alexey Starikovskiy User-Agent: Thunderbird 2.0.0.23 (X11/20090817) MIME-Version: 1.0 To: Henrique de Moraes Holschuh CC: Maxim Levitsky , Alan Jenkins , "Rafael J. Wysocki" , ACPI Devel Maling List , Len Brown , pm list , Thomas Renninger , Matthew Garrett , LKML Subject: Re: [RFC][RFT][PATCH] ACPI: Protection from suspending in the middle of EC transaction References: <201001310029.48717.rjw@sisk.pl> <9b2b86521001310611m339862afw73410dc7eb5692c8@mail.gmail.com> <1264957760.7264.3.camel@maxim-laptop> <20100201094643.GB8740@khazad-dum.debian.net> In-Reply-To: <20100201094643.GB8740@khazad-dum.debian.net> X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1533 Lines: 30 Henrique de Moraes Holschuh пишет: > On Sun, 31 Jan 2010, Maxim Levitsky wrote: >> Unfortunately, this patch even causes regressions on my notebook (it >> survive 63 hibernate cycles), but now I battery driver reports 'battery >> absent', backlight driver reports 0 brightness, but reload helped. > > ... > >> I think that not only _PTS ans _WAK are problematic. What about other >> ACPI drivers that start accessing the EC before it is resumed? >> I think that these cause the problems I observe. > > ACPI drivers might access the EC (even indirectly, through the DSDT). And > platform drivers do often access the EC both at suspend and resume time. Actually, only SBS and thinkpad-acpi access EC directly. All others go through DSDT for access. Still, stopping EC in .suspend is too early, IMHO... > > This needs some sort of strong ordering, the EC must suspend last, and > resume first (as seen by any ACPI and ACPI-aware drivers such as libata, > some platform drivers, etc). If EC interrupts are a problem, maybe it can > be kicked to poll mode for the suspend/resume transition? It's this way already for about a year now... The problem is that EC driver might be stopped in middle of the transaction, thus leaving EC in unknown state for BIOS or switch-over kernel. -- 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/