• Rafael J. Wysocki's avatar
    intel_idle: Use ACPI _CST on server systems · e6d4f08a
    Rafael J. Wysocki authored
    In many cases, especially on server systems, it is desirable to avoid
    enabling C-states that have been disabled in the platform firmware
    (BIOS) setup, except for C1E.
    
    As a rule, the C-states disabled this way are not listed by ACPI
    _CST, so if that is used by intel_idle along with the specific
    table of C-states that it has for the given processor, the C-states
    disabled through the platform firmware will not be enabled by default
    by intel_idle.
    
    Accordingly, set the use_acpi flag (introduced previously) in all
    server processor profiles defined in intel_idle (so as to make it use
    ACPI _CST to decide which C-states to enable by default) and set
    the CPUIDLE_FLAG_ALWAYS_ENABLE flag (also introduced previously)
    for C1E in all C-states tables in intel_idle that contain C1 too
    (so that C1E is enabled regardless of whether or not it is listed
    by ACPI _CST).
    Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
    e6d4f08a
intel_idle.c 41.5 KB