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

From: Pavel Machek
Date: Thu Aug 09 2007 - 11:16:39 EST


Hi!

> > firmwarekit-discuss <firmwarekit-discuss@xxxxxxxxxxx> (added to CC list)
> > see: http://linuxfirmwarekit.org/
> >
> > But if I understand this problem right, this won't be easy.
> > The ACPI tables are just parsed with system ("iasl ...") and syntactical
> > errors/warnings are printed out.
> > I also thought about a test, interpreting the DSDT and read out values
> > of cpufreq tables and sanity check them. AFAIK the linuxfirmwarekit is
> > not designed for that atm. You need to compile in most parts of the
> > acpica code and parse and interpret DSDT/SSDT code yourself in the
> > firmwarekit core or inside a plugin, then do a walk_namespace call or
> > whatever to find the functions/parts you like to examine. This is a lot
> > work and needs a proper design (providing an interface to plugins to let
> > them easily check specific AML/ASL code).
>
> Furthermore, we don't really know what we're looking for. How can you
> tell a given write to an ioport is issuing STANDBYNOW to an ATA disk or
> trying to power the machine off? Adding to the fun, many modern ATA
> controller have more than one way to issue a command. Maybe we can
> match accesses inside regions specified by PCI BARs.... :-(

Hmmm... perhaps we should do it the other way. ACPI is allowed to
touch the embedded controller, what else? Maybe we should warn as soon
as API touches non-EC I/O port?
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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