• Sudeep Holla's avatar
    ACPI / processor_idle: Add support for Low Power Idle(LPI) states · a36a7fec
    Sudeep Holla authored
    ACPI 6.0 introduced an optional object _LPI that provides an alternate
    method to describe Low Power Idle states. It defines the local power
    states for each node in a hierarchical processor topology. The OSPM can
    use _LPI object to select a local power state for each level of processor
    hierarchy in the system. They used to produce a composite power state
    request that is presented to the platform by the OSPM.
    
    Since multiple processors affect the idle state for any non-leaf hierarchy
    node, coordination of idle state requests between the processors is
    required. ACPI supports two different coordination schemes: Platform
    coordinated and  OS initiated.
    
    This patch adds initial support for Platform coordination scheme of LPI.
    Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
    Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
    a36a7fec
bus.c 30.4 KB