Arch Linux

Vrob

Member

Registered: 2007-12-07

Posts: 42

e_powersaver: invalid argument

Hey everyone,

my little home server runs on a via epia board with an C7 CPU. I've been using the e_powersaver module for quite a while now to scale down freq/voltage during idle.
This used to work flawlessly. Since I skipped like two kernel upgrades (I try to reboot the machine as seldomly as possible of course) I can't really pinpoint the upgrade
which skrewed thing up, but I'm pretty sure it was after the bump to linux-3.2.

Anyway, I have e_powersaver in my MODULES array in /etc/rc.conf:

MODULES=(cpufreq_ondemand e_powersaver via_rng)

During bootup and when trying to modprobe the module manually I get the following error:

 $  sudo modprobe e_powersaver
ERROR: could not insert 'e_powersaver': Invalid argument

My dmesg says:

[   74.011494] hwmon_vid: Using 6-bit VID table for VIA C7 CPU
[  510.550021] eps: Detected VIA Model D C7
[  510.550032] eps: Current voltage = 1180mV
[  510.550036] eps: Current multiplier = 9
[  510.550040] eps: Highest voltage = 1196mV
[  510.550044] eps: Highest multiplier = 9
[  510.550048] eps: Lowest voltage = 956mV
[  510.550052] eps: Lowest multiplier = 4
[  510.550056] eps: Your processor is running at different voltage then its maximum. Aborting.
[  510.550061] eps: You can use voltage_failsafe_off option to disable this check.

Ok, though I think, this diffent voltage thingy is another issue I tried that module param... without success:

 $  sudo modprobe e_powersaver voltage_failsafe_off=1
ERROR: could not insert 'e_powersaver': Invalid argument

At least it makes that voltage message go away, but still the module won't load

[  677.528761] eps: Detected VIA Model D C7
[  677.528771] eps: Current voltage = 1180mV
[  677.528776] eps: Current multiplier = 9
[  677.528780] eps: Highest voltage = 1196mV
[  677.528783] eps: Highest multiplier = 9
[  677.528788] eps: Lowest voltage = 956mV
[  677.528791] eps: Lowest multiplier = 4
[  677.528932] eps: ACPI limit 1.80GHz
[  677.528936] eps: Aborting.

It would greatly help me, if the module told me which parameter is invalid or expected. My guess would be, that it now
awaits some parameter that is not given in my current setup and thus having a null value which is invalid.

Also, using acpi-cpufreq is not an option, since it didn't scale down the freq at all in my little test run,

Anyone got an idea?

Thanks,
Vrob

Last edited by Vrob (2012-02-17 10:31:48)

Vrob

Member

Registered: 2007-12-07

Posts: 42

Re: e_powersaver: invalid argument

Ok, today I tried setting all of the parameter that modinfo lists for the e_powersaver module:

$  sudo modinfo e_powersaver
filename:       /lib/modules/3.2.6-2-ARCH/kernel/drivers/cpufreq/e_powersaver.ko.gz
license:        GPL
description:    Enhanced PowerSaver driver for VIA C7 CPU's.
author:         Rafal Bilski <rafalbilski@interia.pl>
depends:        freq_table,processor
intree:         Y
vermagic:       3.2.6-2-ARCH SMP preempt mod_unload modversions 686
parm:           freq_failsafe_off:Disable current vs max frequency check (int)
parm:           voltage_failsafe_off:Disable current vs max voltage check (int)
parm:           ignore_acpi_limit:Don't check ACPI's processor speed limit (int)
parm:           set_max_voltage:Set maximum CPU voltage (mV) C7-M only (int)

$  sudo modprobe e_powersaver freq_failsafe_off=1
ERROR: could not insert 'e_powersaver': Invalid argument

 $  sudo modprobe e_powersaver voltage_failsafe_off=1
ERROR: could not insert 'e_powersaver': Invalid argument

$  sudo modprobe e_powersaver  ignore_acpi_limit=1
ERROR: could not insert 'e_powersaver': Invalid argument

(set_max_voltage doesn't apply since I have no C7-M but only standard C7 cpu)

What I also stumbled over that added to my feeling that this seems to be some bug either upstream or in arch is that when using acpi_cpufreq, cpufreq-info with the ondemand govenor always reports the cpu running at 1.8 GHz, but checking /proc/cpuinfo
seems to yield way more accurate info as it tells me the freq is 800 MHz in idle, while at 1.8 GHz under load...

Greets,
Vrob