• Srinivas Pandruvada's avatar
    cpufreq: intel_pstate: Prioritize firmware-provided balance performance EPP · 2719675f
    Srinivas Pandruvada authored
    The platform firmware can provide a balance performance EPP value by
    enabling HWP and programming the EPP to the desired value.
    
    However, currently this only takes effect for processors listed in
    intel_epp_balance_perf[], so in order to enable a new processor model
    to utilize this mechanism, that table needs to be updated.  It arguably
    should not be necessary to modify the kernel to work properly with
    every new generation of processors, though, and distributions that don't
    always ship the most recent kernels should be able to run reasonably well
    on new hardware without code changes.
    
    For this reason, move the check to avoid updating the EPP when the balance
    performance EPP is unmodified from the power-up default of 0x80 after the
    check that allows the firmware-provided balance performance EPP value to
    be retrieved.  This will cause the code to always look for the firmware-
    provided value before consulting intel_epp_balance_perf[] and the handling
    of new hardware will not depend on whether or not that thable has been
    updated yet.
    Signed-off-by: default avatarSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
    [ rjw: Subject and changelog edits ]
    Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
    2719675f
intel_pstate.c 90 KB