linux-kernel - Re: [PATCH 2/2] gpiolib-acpi: Don't set GPIOs for wakeup in S3 mode

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Date:   Mon, 23 Jan 2023 20:21:19 +0200
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Raul Rangel <rrangel@...omium.org>
Cc:     Bartosz Golaszewski <brgl@...ev.pl>,
        Mario Limonciello <mario.limonciello@....com>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Benjamin Tissoires <benjamin.tissoires@...hat.com>,
        Wolfram Sang <wsa@...nel.org>,
        "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
        Nathan Smythe <ncsmythe@...uboak.org>,
        linux-gpio@...r.kernel.org, linux-acpi@...r.kernel.org,
        linux-kernel@...r.kernel.org, Mark Hasemeyer <markhas@...omium.org>
Subject: Re: [PATCH 2/2] gpiolib-acpi: Don't set GPIOs for wakeup in S3 mode

On Mon, Jan 23, 2023 at 10:54:29AM -0700, Raul Rangel wrote:
> On Mon, Jan 23, 2023 at 10:30 AM Andy Shevchenko
> <andriy.shevchenko@...ux.intel.com> wrote:
> > On Mon, Jan 23, 2023 at 08:55:02AM -0700, Raul Rangel wrote:
> > > On Mon, Jan 23, 2023 at 8:03 AM Bartosz Golaszewski <brgl@...ev.pl> wrote:
> > > > On Sat, Jan 21, 2023 at 2:48 PM Mario Limonciello
> > > > <mario.limonciello@....com> wrote:

...

> > > We still need to figure out a proper fix for this. If you read my post
> > > here: https://gitlab.freedesktop.org/drm/amd/-/issues/2357#note_1732372
> > > I think we misinterpreted what the SharedAndWake bit is used for. To
> > > me it sounds like it's only valid for HW Reduced ACPI platforms, and
> > > S0ix. My changes made it so we call `dev_pm_set_wake_irq` when the
> > > Wake bit is set. Does anyone have any additional context on the Wake
> > > bit? I think we either need to make `dev_pm_set_wake_irq` (or a
> > > variant) only enable the wake on S0i3, or we can teach the ACPI
> > > subsystem to manage arming the IRQ's wake bit. Kind of like we already
> > > manage the GPE events for the device.
> >
> > From the spec:
> >
> > Shared is an optional argument and can be one of Shared, Exclusive,
> > SharedAndWake or ExclusiveAndWake. If not specified, Exclusive is assumed.
> > The “Wake” designation indicates that the interrupt is capable of waking
> > the system from a low-power idle state or a system sleep state. The bit
> > field name _SHR is automatically created to refer to this portion of
> > the resource descriptor.
> >
> >
> > Note: "...a low-power idle state or a system sleep state.". I believe it
> > applies to both.
> 
> Without the _PRW, how do we determine the valid system sleep states
> the device can wake the system from?

Good question. I believe you need to ask somebody from ASWG for the
clarifications.

-- 
With Best Regards,
Andy Shevchenko