From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nebojsa Trpkovic Subject: acpi-cpufreq dissapires when FSB is changed Date: Thu, 18 Oct 2007 17:45:51 +0200 Message-ID: <47177FAF.2070206@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: cpufreq-bounces@lists.linux.org.uk Errors-To: cpufreq-bounces+glkc-cpufreq=m.gmane.org+glkc-cpufreq=m.gmane.org@lists.linux.org.uk To: cpufreq@www.linux.org.uk kernel 2.6.23 intel p35 board core2duo e6750 (6x333=2000MHz, 8x333=2667MHz) when it runs on default FSB (333MHz) it looks like this: uname -a Linux tnt 2.6.23-gentoo #3 SMP Sun Oct 21 15:37:59 CEST 2007 x86_64 Intel(R) Core(TM)2 Duo CPU E6750 @ 2.66GHz GenuineIntel GNU/Linux ls -lah /sys/devices/system/cpu/cpu0/cpufreq/ total 0 drwxr-xr-x 4 root root 0 Oct 18 17:19 . drwxr-xr-x 6 root root 0 Oct 18 17:19 .. -r--r--r-- 1 root root 4.0K Oct 18 17:24 affected_cpus -r--r--r-- 1 root root 4.0K Oct 18 17:24 cpuinfo_max_freq -r--r--r-- 1 root root 4.0K Oct 18 17:24 cpuinfo_min_freq drwxr-xr-x 2 root root 0 Oct 18 17:24 ondemand -r--r--r-- 1 root root 4.0K Oct 18 17:24 scaling_available_frequencies -r--r--r-- 1 root root 4.0K Oct 18 17:24 scaling_available_governors -r--r--r-- 1 root root 4.0K Oct 18 17:24 scaling_cur_freq -r--r--r-- 1 root root 4.0K Oct 18 17:24 scaling_driver -rw-r--r-- 1 root root 0 Oct 18 17:19 scaling_governor -rw-r--r-- 1 root root 4.0K Oct 18 17:24 scaling_max_freq -rw-r--r-- 1 root root 4.0K Oct 18 17:24 scaling_min_freq drwxr-xr-x 2 root root 0 Oct 18 17:24 stats cat /proc/cpuinfo |grep MHz cpu MHz : 2000.000 cpu MHz : 2000.000 when FSB is changed (400MHz) it looks like this: uname -a Linux tnt 2.6.23-gentoo #3 SMP Sun Oct 21 15:37:59 CEST 2007 x86_64 Intel(R) Core(TM)2 Duo CPU E6750 @ 2.66GHz GenuineIntel GNU/Linux ls -lah /sys/devices/system/cpu/cpu0/cpufreq/ ls: cannot access /sys/devices/system/cpu/cpu0/cpufreq/: No such file or directory cat /proc/cpuinfo |grep MHz cpu MHz : 3200.000 cpu MHz : 3200.000 the only thing that was changed in BIOS is FSB freq. no power-saving options were changed. so, in other operating systems frequency scaling continue to work using the same multiplier-voltage data (for e6750 it's 1.15V for 6x and 1.35V for 8x). it leads to 2.4GHz @1.15V and 3.2GHz @1.35V and that is far from unstable for this CPU (the one I own is rock stable at 2.4GHz @1.01V and 3.2GHz @1.26V). before this Intel CPU, I had experiance with Athlon64 CPUs and powernow-k8 cpufreq driver. it has been using multiplier-voltage data no matter what FSB freq was specified, just like windows does with core2duo CPUs. that was much more flexibile and usefull. here, I guess, acpi-cpufreq can not locate data for 2.4GHz and 3.2GHz freqs and fails to work. is there any way to make acpi-cpufreq use multiplier-voltage instead of frequency-voltage pairs?