From: "Bernat, Yehezkel" <yehezkel.bernat@intel.com>
To: "mario.limonciello@dell.com" <mario.limonciello@dell.com>
Cc: "mika.westerberg@linux.intel.com"
<mika.westerberg@linux.intel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"platform-driver-x86@vger.kernel.org"
<platform-driver-x86@vger.kernel.org>,
"dvhart@infradead.org" <dvhart@infradead.org>,
"hughsient@gmail.com" <hughsient@gmail.com>
Subject: Re: [PATCH] Add driver to force WMI Thunderbolt controller power status
Date: Wed, 6 Sep 2017 19:46:14 +0000 [thread overview]
Message-ID: <1504727178.2677.158.camel@intel.com> (raw)
In-Reply-To: <1504726863.2677.154.camel@intel.com>
(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.
next prev parent reply other threads:[~2017-09-06 19:46 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-06 17:54 [PATCH] Add driver to force WMI Thunderbolt controller power status Mario Limonciello
[not found] ` <CA+CmpXt9EtzObijHT3gmm=xUwFDF3Ec=SFbNnPAk+oRdzAUADQ@mail.gmail.com>
2017-09-06 19:40 ` Fwd: " Bernat, Yehezkel
2017-09-06 19:46 ` Bernat, Yehezkel [this message]
2017-09-06 19:49 ` Mario.Limonciello
2017-09-06 20:09 ` Darren Hart
2017-09-06 20:26 ` Bernat, Yehezkel
2017-09-06 21:40 ` Mario.Limonciello
2017-09-06 22:27 ` Darren Hart
2017-09-06 22:34 ` Bernat, Yehezkel
2017-09-07 1:38 ` Mario.Limonciello
2017-09-06 21:43 ` Mario.Limonciello
2017-09-07 6:36 ` Mika Westerberg
2017-09-07 6:50 ` Mika Westerberg
2017-09-07 18:47 ` Mario.Limonciello
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