From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: device_suspend() levels [was Re: [patch] ACPI work on aic7xxx] Date: Tue, 27 Jul 2004 21:16:55 -0400 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <1090977414.18239.28.camel@gaston> References: <40FD38A0.3000603@optonline.net> <20040720155928.GC10921@atrey.karlin.mff.cuni.cz> <40FD4CFA.6070603@optonline.net> <20040720174611.GI10921@atrey.karlin.mff.cuni.cz> <40FD6002.4070206@optonline.net> <1090347939.1993.7.camel@gaston> <40FD65C2.7060408@optonline.net> <1090350609.2003.9.camel@gaston> <40FD82B1.8030704@optonline.net> <1090356079.1993.12.camel@gaston> <40FD85A3.2060502@optonline.net> <1090357324.1993.15.camel@gaston> <410280E9.5040001@optonline.net> <1090684826.1963.6.camel@gaston> <41029215.1030406@optonline.net> <1090694118.1971.13.camel@gaston> <4102FC9D.1060100@optonline.net> <1090793440.1987.2.camel@gaston> <41050EEA.5040107@optonline.net> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from gate.crashing.org ([63.228.1.57]:36570 "EHLO gate.crashing.org") by vger.kernel.org with ESMTP id S266749AbUG1BXO (ORCPT ); Tue, 27 Jul 2004 21:23:14 -0400 In-Reply-To: <41050EEA.5040107@optonline.net> List-Id: linux-scsi@vger.kernel.org To: Nathan Bryant Cc: linux-scsi@vger.kernel.org, Pavel Machek > For suspend/resume and also initialization on bootup. We're not saving > the chip state for PIIX so I assume we're hoping that ACPI does it for us ah, that part, yes, well, we hope ;) though it may just come back up in the right state for normal PIO access, and we do restore the DMA state by calling dma_check again in the ide-disk wakeup code. > > We need to issue the stuff from the low level driver (like aix7xxx) or > > the disk, that is sd, but we should make sure sg etc... also properly > > call the stuff, actually, look at IDE, I defined the special power > > request to act as a state machine once down the queue so the ide layer > > acts differently for disks, cdroms, etc... by sending appropriate > > commands like standby for disks. > > There's another one - synchronize cache or disable write back cache on > the drive.... Yes, whatever. STANDBYNOW1 is enough on IDE (it does sync. the cache), though I don't think we "restore" the state of the write back cache, so that could be a good idea to add too :) Ben