Hi Linus, lkml, The following patches add CPU frequency and volatage scaling support (Intel SpeedStep, AMD PowerNow, etc.) to kernel 2.5.32 Patch 1/4: cpufreq-core ----------------------- The cpufreq core offers a common interface to the CPU clock speed features of ARM, PPC and x86 CPUs. For communication with user space, sysctl entries are placed in /proc/sys/cpu/{0,1,...,NR_CPUS-1}/ . Entries provided are: speed-min (readonly) speed-max (readonly) speed-sync (readonly - all CPUs need the same frequency, changes affect all CPUs) speed (read/write) In order for this code to be built, an architecture must define the CONFIG_CPU_FREQ configuration symbol. The merged ARM code already has the necessary configuration in place, the i386 code follows in parts 2 and 3. Specifically on ARM CPUs, the core is especially important, since various ARM system on a chip implementations derive peripheral clocks from the CPU clock (eg, LCD controllers, SDRAM controllers, etc). The core allows these peripherals to take action either prior and/or after the actual CPU clock adjustment so we don't go out of tolerance. Patch 2/4: cpufreq-i386-core ---------------------------- The main part of this patch is a CPUFreq notifier in arch/i386/kernel/time.c. It updates the i386-specific cpu_khz, cpu_data[].loops_per_jiffy and fast_gettimeoffset_quotient on each frequency change. Additionally, this patch allows "cpu_khz" to be exported (it is needed for some cpufreq drivers) and adds some MSR #defines to asm-i386/msr.h Patch 3/4: cpufreq-i386-drivers ------------------------------- Four i386 CPUFreq drivers are ready to be merged this time. These are: elanfreq.c: The AMD Elan CPU family offers extensive clock scaling longhaul.c: VIA Longhaul processor clock + voltage scaling powernow-k6.c: mobile AMD K6-2+ / mobile AMD K6-3+ clock scaling speedstep.c: clock and voltage scaling on mobile Intel Pentium 3 and 4s, but (unfortunately) only on ICH2-M or ICH3-M based chipsets. Support for mobile AMD K7 processors is still in development. Patch 4/4: cpufreq-doc ---------------------- an entry to the CREDITS and the MAINTAINERS file, Config.help texts, and extensive documentation in linux/Documentation/cpufreq Comments welcome; however please ensure that the cpufreq development list at cpufreq@www.linux.org.uk receives a copy of all comments. Dominik