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    cpufreq: pcc: Enable autoload of pcc-cpufreq for ACPI processors · 7e7e8fe6
    Lenny Szubowicz authored
    The pcc-cpufreq driver is not automatically loaded on systems where
    the platform's power management setting requires this driver.
    Instead, on those systems no CPU frequency driver is registered and
    active.
    
    Make the autoloading matching criteria for loading the pcc-cpufreq
    driver the same as done in acpi-cpufreq by commit c655affb
    
    
    ("ACPI / cpufreq: Add ACPI processor device IDs to acpi-cpufreq").
    
    x86 CPU frequency drivers are now typically autoloaded by specifying
    MODULE_DEVICE_TABLE entries and x86cpu model specific matching.
    But pcc-cpufreq was omitted when acpi-cpufreq and other drivers were
    changed to use this approach.
    
    Both acpi-cpufreq and pcc-cpufreq depend on a distinct and mutually
    exclusive set of ACPI methods which are not directly tied to specific
    processor model numbers. Both of these drivers have init routines
    which look for their required ACPI methods. As a result, only the
    appropriate driver registers as the cpu frequency driver and the other
    one ends up being unloaded.
    
    Tested on various systems where acpi-cpufreq, intel_pstate, and
    pcc-cpufreq are the expected cpu frequency drivers.
    
    Signed-off-by: default avatarLenny Szubowicz <lszubowi@redhat.com>
    Signed-off-by: default avatarJoseph Szczypek <joseph.szczypek@hp.com>
    Reported-by: default avatarTrinh Dao <trinh.dao@hp.com>
    Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
    7e7e8fe6