lkml.org 
[lkml]   [2017]   [Sep]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: Fwd: [PATCH] Add driver to force WMI Thunderbolt controller power status
Date

> 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.
\
 
 \ /
  Last update: 2017-09-06 21:41    [W:0.092 / U:0.084 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site