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    SubjectRe: [Acpi4asus-user] [PATCH 1/1] cpufreq: eeepc 900 frequency scaling driver
    >> Could it happen that upcoming machines provide this interface (the two ACPI
    >> functions) and also can do real CPU frequency/volt switching, e.g. via
    >> acpi-cpufreq?
    > Probably this interface is a solution specific to machines based on the
    > celeron M: I don't even know if other 'old' models provide the same
    > interface.

    We I just received another patch for that (adding a cpufv file in
    sysfs) and I don't really know what to do.

    As Grigori Goronzy said, using cpufreq in not a good idea:

    > 1) dynamic governors like "ondemand" or "conservative" are not suitable
    > for SHE. It's possible to avoid usage of these by specifying a long
    > (e.g. UINT_MAX) transition latency. However, the fallback governor is
    > "performance" which isn't a good idea either, because it'll use the
    > overclock setting always. For SHE, the default should be the "normal",
    > non-overclocked frequency.
    > 2) The SHE ACPI interface doesn't expose the clock frequencies. I'm
    > using 750 / 1000 / 1500 KHz at the moment, but that's hacky. cpufreq
    > does not support performance points with names, such as "powersave",
    > "normal", "performance", etc.
    > 3) It looks like it is impossible to use more than one cpufreq driver
    > per CPU. This effectively means you can either use the regular ACPI
    > frequency scaling, which switches between multipliers, or SHE. That's
    > unacceptable. SHE is not intended to replace the regular frequency
    > scaling, but to complement it.

    But adding another specific file for eeepc seems ugly too.
    Does someone have a great idea to solve that ?

    Corentin Chary

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