(Resending with a fixed CC list. Sorry.) > Current implementations of Intel Thunderbolt controllers will go > into a low power mode when not in use. > > Many machines containing these controllers also have a GPIO wired up > that can force the controller awake. This is offered via a ACPI-WMI > interface intended to be manipulated by a userspace utility. > This mechanism is provided by Intel to OEMs to include in BIOS. > It uses an industry wide GUID that is populated in a separate _WDG > entry with no binary MOF. > > This interface allow software such as fwupd to wake up thunderbolt > controllers to query the firmware version or flash new firmware. As this is a Thunderbolt specific function, maybe it's better to be exposed from the Thunderbolt driver? > + > +static DEVICE_ATTR_WO(force_power); > + I'm not sure what is the convention for permissions for this type of attributes but I feel like this worth being root-only writable, as it can be used to power-off the controller in the middle of a FW update, for example.
