Re: [PATCH] powernow-k8 max speed sanity check

From: Tony Lindgren
Date: Thu Feb 05 2004 - 13:19:03 EST


* Pavel Machek <pavel@xxxxxx> [040205 06:03]:
> Hi!
>
> > Following is a little patch to do a sanity check on the max speed and
> > voltage values provided by the bios.
> >
> > Some buggy bioses provide bad values if the cpu changes, for example, in
> > my case the bios claims the max cpu speed is 1600MHz, while it's running at
> > 1800MHz. (Cheapo Emachines m6805 you know...) This could also happen on
> > machines where the cpu is upgraded.
> >
> > These checks should be safe, as they only change things if the machine is
> > already running at a higher speed than the bios claims.
> >
>
> Someone should really bug them to fix their BIOS. (BTW does keyboard work
> ok for you?)

No problems with keyboard, and the cpufreq works fine with the patch, but
not at all without the patch.

There are some ACPI related issues though, such as: via-rhine gets wrong
irq with ACPI on, system hangs with yenta_socket loaded if I
connect/disconnect the power cord... So for now, I don't use the PCMCIA.

> Going though ACPI solves this, and I have perhaps better
> patch to hardcode right values...

Still, the max speed check should be safe. Maybe pass values as module
options too? I would not trust on ACPI working right on this machine :)

Tony
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