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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Nathan Bryant <nbryant@optonline.net>
Cc: linux-scsi@vger.kernel.org, Pavel Machek <pavel@ucw.cz>
Subject: Re: device_suspend() levels [was Re: [patch] ACPI work on aic7xxx]
Date: Tue, 27 Jul 2004 21:16:55 -0400	[thread overview]
Message-ID: <1090977414.18239.28.camel@gaston> (raw)
In-Reply-To: <41050EEA.5040107@optonline.net>


> 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
 


      reply	other threads:[~2004-07-28  1:23 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-07-20 15:22 [patch] ACPI work on aic7xxx Nathan Bryant
2004-07-20 15:59 ` Pavel Machek
2004-07-20 16:48   ` Nathan Bryant
2004-07-20 17:46     ` device_suspend() levels [was Re: [patch] ACPI work on aic7xxx] Pavel Machek
2004-07-20 18:10       ` Nathan Bryant
2004-07-20 18:25         ` Benjamin Herrenschmidt
2004-07-20 18:34           ` Nathan Bryant
2004-07-20 19:10             ` Benjamin Herrenschmidt
2004-07-20 19:23               ` Pavel Machek
     [not found]               ` <40FD82B1.8030704@optonline.net>
     [not found]                 ` <1090356079.1993.12.camel@gaston>
     [not found]                   ` <40FD85A3.2060502@optonline.net>
     [not found]                     ` <1090357324.1993.15.camel@gaston>
     [not found]                       ` <410280E9.5040001@optonline.net>
     [not found]                         ` <1090684826.1963.6.camel@gaston>
     [not found]                           ` <41029215.1030406@optonline.net>
     [not found]                             ` <1090694118.1971.13.camel@gaston>
2004-07-25  0:19                               ` Nathan Bryant
2004-07-25 22:10                                 ` Benjamin Herrenschmidt
2004-07-26  7:32                                   ` Andre Hedrick
2004-07-28  1:18                                     ` Benjamin Herrenschmidt
2004-07-26 14:02                                   ` Nathan Bryant
2004-07-28  1:16                                     ` Benjamin Herrenschmidt [this message]

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