acpi_cpufreq doesn't load: No such device

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robisz
Posts: 1
Joined: Wed 25. Feb 2009, 09:57

acpi_cpufreq doesn't load: No such device

Post by robisz » Wed 25. Feb 2009, 10:01

I have a Shuttle K48 barebone PC with Core 2 Duo E5200 CPU and I cannot get SpeedStep to work (CPU stays at max). I'm using Ubuntu 8.10. I've tried to use linux-phc without success:

$ sudo modprobe acpi_cpufreq
FATAL: Error inserting acpi_cpufreq (/lib/modules/2.6.27-11-generic/kernel/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.ko): No such device

Any ideas? Thanks in advance.

$ cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 23
model name : Pentium(R) Dual-Core CPU E5200 @ 2.50GHz
stepping : 6
cpu MHz : 2502.575
cache size : 2048 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 2
apicid : 0
initial apicid : 0
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc arch_perfmon pebs bts pni monitor ds_cpl est tm2 ssse3 cx16 xtpr lahf_lm
bogomips : 5005.15
clflush size : 64
power management:

processor : 1
vendor_id : GenuineIntel
cpu family : 6
model : 23
model name : Pentium(R) Dual-Core CPU E5200 @ 2.50GHz
stepping : 6
cpu MHz : 2502.575
cache size : 2048 KB
physical id : 0
siblings : 2
core id : 1
cpu cores : 2
apicid : 1
initial apicid : 1
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc arch_perfmon pebs bts pni monitor ds_cpl est tm2 ssse3 cx16 xtpr lahf_lm
bogomips : 5005.14
clflush size : 64
power management:

the-fallen
Administrator
Posts: 346
Joined: Wed 9. Jul 2008, 19:57

Re: acpi_cpufreq doesn't load: No such device

Post by the-fallen » Wed 25. Feb 2009, 15:34

Does it work with an unpatched acpi-cpufreq? Can you select frequencies with the unpatched module?

Most tines those E - CPUs are not capable of doing what we do because they are not designet to reduce speed and save energy (because they are designed for a Desktop Computer where energy and cooling are no problems.

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.yankee
Posts: 2
Joined: Thu 12. Mar 2009, 03:17

Re: acpi_cpufreq doesn't load: No such device

Post by .yankee » Thu 12. Mar 2009, 03:41

I get the same error.
My cpu is Intel Atom 330 (the dual core one) - mb D945GCLF2.
kernel: 2.6.27-gentoo-r8
I must say I was very surprised from the beginning, when I've read somewhere here that PHC had been tested on Atom. I thought it didn't support any type of frequency manipulation...

Anyway, it didn't work so far - will see about the original acpi-cpufreq in a moment.

EDIT:
Yep, no-go with cpu-freq module after reversing the patch either:

Code: Select all

linux # insmod arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.ko
insmod: error inserting 'arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.ko': -1 No such device
If anyone got it working with Atom 330 before, I'd suspect my BIOS to be the problem - it's rather old.

the-fallen
Administrator
Posts: 346
Joined: Wed 9. Jul 2008, 19:57

Re: acpi_cpufreq doesn't load: No such device

Post by the-fallen » Thu 12. Mar 2009, 07:43

It was me it was working for.
I have an Acer AspireOne 110L with the olter N270 Atom CPU.

It simply worked.


So if you can you may try to install another distribution on a pen drive and check it again then or make your own kernel. Just to try... This is more or less a shot into the blue because I have no clue what could be the reason there.

Changing voltages should generally be possible on that CPU i think.

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.yankee
Posts: 2
Joined: Thu 12. Mar 2009, 03:17

Re: acpi_cpufreq doesn't load: No such device

Post by .yankee » Fri 13. Mar 2009, 00:26

the-fallen wrote:It was me it was working for.
I have an Acer AspireOne 110L with the olter N270 Atom CPU.
Well, that's just about what I feared... There is a huge difference between N2xx and 200/300 series. The most important thing in this matter is that the latter don't support SpeedStep - which makes them incapable of frequency/voltage manipulation.

For details, see here:
http://en.wikipedia.org/wiki/List_of_In ... processors

the-fallen
Administrator
Posts: 346
Joined: Wed 9. Jul 2008, 19:57

Re: acpi_cpufreq doesn't load: No such device

Post by the-fallen » Thu 19. Mar 2009, 11:01

Yay! I compared the features of the olter Atom CPUs and the newer ones and you are right, the newer ones are not capable...

They do not have the IEST feature (Intel Enhanced Speed Step).

Maybe you can set Voltages directly using the MSR interface.

Can you check the output of read_msr (downloadable here) and post it here?

I wrote a Python-Based tool to write to MSR directly. Maybe this can help you.

gordan
Posts: 8
Joined: Thu 22. Apr 2010, 23:12

Re: acpi_cpufreq doesn't load: No such device

Post by gordan » Fri 16. Jul 2010, 12:53

Just in case anyone comes across this - Atom 330 doesn't support EIST, only standard speed-step. So you can change the clock speed, but not the voltages.

phc-intel won't work on the Atom 330, nor will the vanilla acpi_cpufreq work. Most people use the default settings for cpuspeed , which seem to not work on most things (Ubuntu, RHEL6 and probably FC11+, probably earlier, too). The problem isn't in the frequency driver, it is in the governor. The p4_clockmod frequency scaling driver works fine.

The problem is that the governor defaults to "ondemand". That won't work, for some reason. "conservative" doesn't work, either. "userspace", however, does work. When I switch to that, the clock speeds reliably and gradually drop to 200MHz. The comments in /etc/sysconfig/cpuspeed imply that without acpi_cpufreq the governor should default to userspace, but it quite clearly does not - probably a bug in cpuspeed or at least the documentation.

It seems that Atom doesn't support self-throttling (possibly not a feature of standard speed-step), so it relies on the userspace app to adjust the multiplier manually).

Anyway, all you should need to do is set the governor to userspace, and the frequency scaling should then work fine. This should still provide an 8x power savings at idle, even without dropping the voltages. :)

HTH.

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