Re: Speedstep on centrino

From: Jeremy Fitzhardinge
Date: Thu Apr 22 2004 - 05:19:57 EST

On Sun, 2004-04-18 at 11:56, Alexander Hoogerhuis wrote:
> I've been twaddling with getting SpeedStep right on my laptop (HP
> nc6000, 1.6GHz P-M) and noticed a few odd things:
> Using regular SpeedStep is says to use speedstep-centrino due to
> voltage regultion, etc.

Yep, that's reasonable.

> Using SpeedStep for Centrino og gived me this line on boot:
> speedstep-centrino: found "Intel(R) Pentium(R) M processor 1600MHz": max frequency: 1600000kHz

Looks normal.

> This seems to work and make the battery last an useful amount of time.


> Using SpeedStep for Centrino with decoding the speeds and voltages
> (CONFIG_X86_SPEEDSTEP_CENTRINO_ACPI) will not yield any output during
> boot regarding cpufreq at all and the battery useage is heavy. ACPI is
> enabled.

I've never managed to get ACPI working on my laptop, so I haven't tested
this. I'm not sure what's going on here - maybe someone on the cpufreq
list can help.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at