Cannot create phc_vids file

If you have trouble with PHC you can ask and hope for help here.
Post Reply
Rogge
Posts: 1
Joined: Tue 7. Dec 2010, 16:08

Cannot create phc_vids file

Post by Rogge » Fri 21. Jan 2011, 10:15

Hi, I'm using linux-phc on a Core 2 Duo T7200 and

Linux wrath 2.6.35-24-generic-phc #42~phc0-Ubuntu SMP Wed Dec 22 14:09:36 UTC 2010 x86_64 GNU/Linux

It worked fine until the recent update to 2.6.35-24. I have entries in my /etc/rc.local that create the phc_vids files for cpu0 and cpu1. However, voltage regulation does not work anymore.

When trying to echo the values manually (or even just touch the phc_vids files), the system says there's no such file or directory:

root@wrath:/sys/devices/system/cpu/cpu0/cpufreq# ll
total 0
drwxr-xr-x 4 root root 0 2011-01-21 07:18 ./
drwxr-xr-x 7 root root 0 2011-01-21 07:18 ../
-r--r--r-- 1 root root 4096 2011-01-21 07:21 affected_cpus
-r--r--r-- 1 root root 4096 2011-01-21 07:21 bios_limit
-r-------- 1 root root 4096 2011-01-21 07:21 cpuinfo_cur_freq
-r--r--r-- 1 root root 4096 2011-01-21 07:18 cpuinfo_max_freq
-r--r--r-- 1 root root 4096 2011-01-21 07:21 cpuinfo_min_freq
-r--r--r-- 1 root root 4096 2011-01-21 07:21 cpuinfo_transition_latency
drwxr-xr-x 2 root root 0 2011-01-21 07:21 ondemand/
-r--r--r-- 1 root root 4096 2011-01-21 07:21 related_cpus
-r--r--r-- 1 root root 4096 2011-01-21 07:18 scaling_available_frequencies
-r--r--r-- 1 root root 4096 2011-01-21 07:18 scaling_available_governors
-r--r--r-- 1 root root 4096 2011-01-21 07:18 scaling_cur_freq
-r--r--r-- 1 root root 4096 2011-01-21 07:21 scaling_driver
-rw-r--r-- 1 root root 4096 2011-01-21 07:19 scaling_governor
-rw-r--r-- 1 root root 4096 2011-01-21 07:21 scaling_max_freq
-rw-r--r-- 1 root root 4096 2011-01-21 07:21 scaling_min_freq
-rw-r--r-- 1 root root 4096 2011-01-21 07:21 scaling_setspeed
drwxr-xr-x 2 root root 0 2011-01-21 07:21 stats/
root@wrath:/sys/devices/system/cpu/cpu0/cpufreq# echo "23 4 1 1" > /sys/devices/system/cpu/cpu0/cpufreq/phc_vids
bash: /sys/devices/system/cpu/cpu0/cpufreq/phc_vids: No such file or directory
root@wrath:/sys/devices/system/cpu/cpu0/cpufreq# echo "23 4 1 1" > /sys/devices/system/cpu/cpu1/cpufreq/phc_vids
bash: /sys/devices/system/cpu/cpu1/cpufreq/phc_vids: No such file or directory

Any solution or hint to track down the problem is welcome. Thanks!

User avatar
PowerPaul86
Posts: 4
Joined: Tue 18. Nov 2008, 16:10

Re: Cannot create phc_vids file

Post by PowerPaul86 » Sat 29. Jan 2011, 11:07

You haven't loaded the phc kernel module, otherwise you would see the phc_* files in that folder.
Also you don't create the phc_vids files with your /etc/rc.local you just fill the file with the string you echo.

What you need to do is download linux-header-2.6.35-24 and rebuild the phc kernel module again.

~/phc-intel-0.3.2-10$ make prepare && make && sudo make install

Then load it with
sudo modprobe phc_intel

Post Reply