In this link, there are a lot of people's m4600 got cpu speed is limit by a special number in bios_limit. And I tried this issue in upstream, 3.2 and 2.6.x. All of them affect by this issue. And this issue can be handle by add "processor.ignore_ppc=1" to command line.
so in what situation when you get the bios_limit? does it happen when you boot with battery or when you remove the power supply? please attach the acpidump output of the laptop. please attach the output of "grep . /sys/devices/system/cpu/cpu*/cpufreq/*"
ping...
I think than I have similar problem. IMHO since kernel 3.7 when I start notebook without power supply, the cpu frequency is stuck on lowest speed, 3.8_rc5 is also broken.
Created attachment 92051 [details] cpu freq grep
Created attachment 92061 [details] acpidump
(In reply to Roman Jarosz from comment #3) > I think than I have similar problem. > IMHO since kernel 3.7 when I start notebook without power supply, the cpu > frequency is stuck on lowest speed, 3.8_rc5 is also broken. Does v3.6 have this problem? AFAIK, if _PPC as provided by firmware told us now the CPU's frequency can't be higher than 800MHZ, then Linux will follow it. THe behavior can be changed by the above mentioned ignore_ppc kernel command line, or you can use intel_pstate cpu frequency driver instead.
any update? Does intel_pstate work?
Bug closed as there is no reponse from the bug reporter. please feel free to reopen it if you can reproduce the problem in latest upstream kernel and provide the information requested in comment #7.