Re: Disk spin down issue on shut down/suspend to disk

[Robert Hancock <hancockr@shaw.ca>]

Tejun Heo wrote:
> Robert Hancock wrote:
> > Tejun Heo wrote:
> > > Michael Sedkowski wrote:
> > > > > Hmmm... If the problem only shows up on nx6325, it might be that
> > > > > ACPI is
> > > > > pulling unnecessary stunt.  Please apply the attached patch and report
> > > > > when the disk spins down and up.
> > > > Disk spins down on "Pre-shutdown prepare" and then goes up and down on
> > > > "Power down".
> > > Oh... crap, so acpi wants to sync cache on shutdown.  I wonder whether
> > > it spins down the disk correctly.  Does emergency unload count increase
> > > after each power down?  Also, please post the result of 'dmidecode'.
> > I know that my Compaq X1000-series laptop does do some kind of ACPI
> > games with the disk on ACPI power off (I assume it is putting the disk
> > in standby before power-off at least). It also does this if you boot
> > into DOS, GRUB, etc. and then hit the power button. Could be if the disk
> > is dumb enough to spin up for sync cache and standby when there is
> > nothing to flush, and the kernel does its own standby, this could cause
> > an extra spinup/down..
>
> Yeah, that seems to be what's going on.  I don't think we have any other
> choice than blacklisting those notebooks.  This is a mess.  How does the
> other OS cope with this?

Quite possible that it gets a double spindown with these laptop/drive 
combinations as well. I don't think it's particularly harmful as long as 
there's no emergency unload..

> I'm thinking about using DMI vendor/product match to detect the affected
> systems but I think it would be better to match the ACPI implementation
> directly.  Is there a way to match specific ACPI implementation?

Don't think it would be very easy, it's presumably being done off some 
SMI code triggered from the ACPI power off register or something, so I'm 
assuming it's nothing the kernel sees in its ACPI tables..

--
Robert Hancock      Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/

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