• Rafael J. Wysocki's avatar
    PM / PCI / ACPI: Kick devices that might have been reset by firmware · 58a1fbbb
    Rafael J. Wysocki authored
    There is a concern that if the platform firmware was involved in
    the system resume that's being completed,  some devices might have
    been reset by it and if those devices had the power.direct_complete
    flag set during the preceding suspend transition, they may stay
    in a reset-power-on state indefinitely (until they are runtime-resumed
    and then suspended again).  That may not be a big deal from the
    individual device's perspective, but if the system is an SoC, it may
    be prevented from entering deep SoC-wide low-power states on idle
    because of that.
    
    The devices that are most likely to be affected by this issue are
    PCI devices and ACPI-enumerated devices using the general ACPI PM
    domain, so to prevent it from happening for those devices, force a
    runtime resume for them if they have their power.direct_complete
    flags set and the platform firmware was involved in the resume
    transition currently in progress.
    Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
    58a1fbbb
pci-driver.c 35.2 KB