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 19:30:45 +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 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:
> > >
> > > commit 1796f808e4bb ("HID: i2c-hid: acpi: Stop setting wakeup_capable")
> > > adjusted the policy to enable wakeup by default if the ACPI tables
> > > indicated that a device was wake capable.
> > >
> > > It was reported however that this broke suspend on at least two System76
> > > systems in S3 mode and two Lenovo Gen2a systems, but only with S3.
> > > When the machines are set to s2idle, wakeup behaves properly.
> > >
> > > Configuring the GPIOs for wakeup with S3 doesn't work properly, so only
> > > set it when the system supports low power idle.
> > >
> > > Fixes: 1796f808e4bb ("HID: i2c-hid: acpi: Stop setting wakeup_capable")
> > > Fixes: b38f2d5d9615c ("i2c: acpi: Use ACPI wake capability bit to set wake_irq")
> > > Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2357
> > > Link: https://bugzilla.redhat.com/show_bug.cgi?id=2162013
> > > Reported-by: Nathan Smythe <ncsmythe@...uboak.org>
> > > Tested-by: Nathan Smythe <ncsmythe@...uboak.org>
> > > Suggested-by: Raul Rangel <rrangel@...omium.org>
> > > Signed-off-by: Mario Limonciello <mario.limonciello@....com>
> > > ---
> > >  drivers/gpio/gpiolib-acpi.c | 3 ++-
> > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
> > > index 9ef0f5641b521..17c53f484280f 100644
> > > --- a/drivers/gpio/gpiolib-acpi.c
> > > +++ b/drivers/gpio/gpiolib-acpi.c
> > > @@ -1104,7 +1104,8 @@ int acpi_dev_gpio_irq_wake_get_by(struct acpi_device *adev, const char *name, in
> > >                                 dev_dbg(&adev->dev, "IRQ %d already in use\n", irq);
> > >                         }
> > >
> > > -                       if (wake_capable)
> > > +                       /* avoid suspend issues with GPIOs when systems are using S3 */
> > > +                       if (wake_capable && acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0)
> > >                                 *wake_capable = info.wake_capable;
> > >
> > >                         return irq;
> > > --
> > > 2.34.1
> > >
> >
> > Applied, thanks!
> >
> > Bart
> 
> 
> 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.

-- 
With Best Regards,
Andy Shevchenko