On 1/3/20 10:18 AM, Al Cooper wrote: > Add the ability to handle USB wake events from USB devices when > in S2 mode. Typically there is some additional configuration > needed to tell the USB device to generate the wake event when > suspended but this varies with the different USB device classes. > For example, on USB Ethernet dongles, ethtool should be used to > enable the magic packet wake functionality in the dongle. > NOTE: This requires that the "power/wakeup" sysfs entry for > the USB device generating the wakeup be set to "enabled". > > This functionality requires a special hardware sideband path that > will trigger the AON_PM_L2 interrupt needed to wake the system from > S2 even though the USB host controllers are in IDDQ (low power state) > and most USB related clocks are shut off. For the sideband signaling > to work we need to leave the usbx_freerun clock running, but this > clock consumes very little power by design. There's a bug in the > XHCI wake hardware so only EHCI/OHCI wake is currently supported. > > Signed-off-by: Al Cooper <alcooperx@xxxxxxxxx> Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx> -- Florian
