• Rafael J. Wysocki's avatar
    ACPI / PM: Do not power manage devices in unknown initial states · b3785492
    Rafael J. Wysocki authored
    In general, for ACPI device power management to work, the initial
    power states of devices must be known (otherwise, we wouldn't be able
    to keep track of power resources, for example).  Hence, if it is
    impossible to determine the initial ACPI power states of some
    devices, they can't be regarded as power-manageable using ACPI.
    For this reason, modify acpi_bus_get_power_flags() to clear the
    power_manageable flag if acpi_bus_init_power() fails and add some
    extra fallback code to acpi_bus_init_power() to cover broken
    BIOSes that provide _PS0/_PS3 without _PSC for some devices.
    Verified to work on my HP nx6325 that has this problem.
    Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
    Tested-by: default avatarPeter Wu <lekensteyn@gmail.com>
scan.c 45.3 KB