Firebird News

Saturday, November 01, 2008

Enabling frequency scaling on my everex cloudbook
after the upgrade to ubuntu intrepid ibex (kernel 2.6.27.x) i have good sound and the syste is moving faster
maybe is because of the new io sheduler 
but the frequency scaling is not enabled (default cpu speed is 600mhz)
so i have compile it 
download the latest stable kernel from

in my case  
$tar -jxvf linux-
$cd /usr/src/linux-
$sudo mv cpufreq /opt/build/
$ cd /opt/build/cpufreq

$vi Makefile
$(MAKE) -C /lib/modules/`uname -r`/build M=`pwd` modules
rm -rf *.o .*.cmd *.ko *.mod.c .tmp_versions Module.symvers
obj-m += e_powersaver.o

Now you need to make it 
$cp e_powersaver.ko /lib/modules/2.6.27-7-generic/kernel/drivers/cpufreq/
$ sudo depmod -ae
$ sudo modprobe e_powersaver
$ cpufreq-set -g performance

now my cpu is idling at 1200 mhz 
cat /proc/cpuinfo
processor : 0
vendor_id : CentaurHauls
cpu family : 6
model : 13
model name : VIA C7-M Processor 1200MHz
stepping : 0
cpu MHz : 1199.952
cache size : 128 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 1
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge cmov pat clflush acpi mmx fxsr sse sse2 tm nx up pni est tm2 xtpr rng rng_en ace ace_en ace2 ace2_en phe phe_en pmm pmm_en
bogomips : 2399.92
clflush size : 64
power management:

a good idea is to put the module at startup too 

another good command line 

analyzing CPU 0:
  driver: e_powersaver
  CPUs which need to switch frequency at the same time: 0
  hardware limits: 400 MHz - 1.20 GHz
  available frequency steps: 400 MHz, 500 MHz, 600 MHz, 700 MHz, 800 MHz, 900 MHz, 1000 MHz, 1.10 GHz, 1.20 GHz
  available cpufreq governors: ondemand, userspace, conservative, powersave, performance
  current policy: frequency should be within 400 MHz and 1.20 GHz.
                  The governor "performance" may decide which speed to use
                  within this range.
  current CPU frequency is 1.20 GHz.

or if you need an low noise system 
$ cpufreq-set -g ondemand

1 comment:

alon said...

Thanks for the notes - I'm going to try that with intrepid on a CE260 (FIC), which from what I saw is basically the same as a cloudbook.

; do you also have the problem that when connecting a headset there is no audio from speakers (as it should be) and from the headset (as it shouldn't be)?