Re: [PATCH 0/2] ACPI: Tiny power button driver

From: Rafael J. Wysocki
Date: Thu Feb 13 2020 - 17:43:26 EST


On Wed, Feb 12, 2020 at 12:36 AM Josh Triplett <josh@xxxxxxxxxxxxxxxx> wrote:
>
> Virtual machines often use an ACPI power button event to tell the
> machine to shut down gracefully.
>
> Provide an extremely lightweight "tiny power button" driver to handle
> this event by signaling init directly, rather than running a separate
> daemon (such as acpid or systemd-logind) that adds to startup time and
> VM image complexity.
>
> I originally proposed a change to the ACPI power button driver to
> introduce an optional path to signal init, but Rafael expressed a
> preference to have this as a separate, mutually exclusive driver
> instead. The result did come out much simpler, conceptually, with the
> added benefit of being able to disable CONFIG_INPUT entirely for a
> kernel that exclusively targets cloud/VM systems.
>
> The first patch in the series just moves HID definitions to
> acpi/button.h in preparation for sharing them with the tiny-power-button
> driver. The second patch provides the driver itself.
>
> Josh Triplett (2):
> acpi: button: move HIDs to acpi/button.h
> acpi: Add new tiny-power-button driver to directly signal init

Applied as 5.7 material, thanks!