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 09:34:40 -0700
From:   Raul Rangel <rrangel@...omium.org>
To:     "Limonciello, Mario" <Mario.Limonciello@....com>
Cc:     Bartosz Golaszewski <brgl@...ev.pl>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Andy Shevchenko <andriy.shevchenko@...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-gpio@...r.kernel.org>,
        "linux-acpi@...r.kernel.org" <linux-acpi@...r.kernel.org>,
        "linux-kernel@...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 9:07 AM Limonciello, Mario
<Mario.Limonciello@....com> wrote:
>
> [Public]
>
>
>
> > -----Original Message-----
> > From: Raul Rangel <rrangel@...omium.org>
> > Sent: Monday, January 23, 2023 09:55
> > To: Bartosz Golaszewski <brgl@...ev.pl>
> > Cc: Limonciello, Mario <Mario.Limonciello@....com>; Mika Westerberg
> > <mika.westerberg@...ux.intel.com>; Andy Shevchenko
> > <andriy.shevchenko@...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 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.
>
> There is an FADT flag for HW reduced (ACPI_FADT_HW_REDUCED).  So
> maybe something on top of my change to look at that too?
>
> IE:
> if (wake_capable && (acpi_gbl_FADT.flags & (ACPI_FADT_LOW_POWER_S0 | ACPI_FADT_HW_REDUCED)

The problem with the ACPI_FADT_LOW_POWER_S0 FADT flag is that it
defines if S0ix is supported. That's not mutually exclusive with S3.
So we really need a runtime check to see which suspend mode we are
entering.