• Srinivas Pandruvada's avatar
    cpufreq: intel_pstate: Use firmware default EPP · 3d13058e
    Srinivas Pandruvada authored
    For some specific platforms (E.g. AlderLake) the balance performance
    EPP is updated from the hard coded value in the driver. This acts as
    the default and balance_performance EPP. The purpose of this EPP
    update is to reach maximum 1 core turbo frequency (when possible) out
    of the box.
    
    Although we can achieve the objective by using hard coded value in the
    driver, there can be other EPP which can be better in terms of power.
    But that will be very subjective based on platform and use cases.
    This is not practical to have a per platform specific default hard coded
    in the driver.
    
    If a platform wants to specify default EPP, it can be set in the firmware.
    If this EPP is not the chipset default of 0x80 (balance_perf_epp unless
    driver changed it) and more performance oriented but not 0, the driver
    can use this as the default and balanced_perf EPP. In this case no driver
    update is required every time there is some new platform and default EPP.
    
    If the firmware didn't update the EPP from the chipset default then
    the hard coded value is used as per existing implementation.
    Signed-off-by: default avatarSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
    Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
    3d13058e
intel_pstate.c 90.4 KB