linux-kernel - Re: [PATCH v5 08/13] ACPI: PM: Take wake IRQ into consideration when entering suspend-to-idle

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Message-ID: <CAJZ5v0g57mF-4ZC2ajL5+JE+q9y=fW1G-OXR8tuOk4TYxHPWtQ@mail.gmail.com>
Date:   Sat, 24 Sep 2022 19:00:19 +0200
From:   "Rafael J. Wysocki" <rafael@...nel.org>
To:     Raul E Rangel <rrangel@...omium.org>
Cc:     ACPI Devel Maling List <linux-acpi@...r.kernel.org>,
        linux-input <linux-input@...r.kernel.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Tim Van Patten <timvp@...gle.com>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        "jingle.wu" <jingle.wu@....com.tw>,
        Hans de Goede <hdegoede@...hat.com>,
        Mario Limonciello <mario.limonciello@....com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Len Brown <lenb@...nel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v5 08/13] ACPI: PM: Take wake IRQ into consideration when
 entering suspend-to-idle

On Wed, Sep 21, 2022 at 5:52 PM Raul E Rangel <rrangel@...omium.org> wrote:
>
> This change adds support for ACPI devices that use ExclusiveAndWake or
> SharedAndWake in their _CRS GpioInt definition (instead of using _PRW),
> and also provide power resources. Previously the ACPI subsystem had no
> idea if the device had a wake capable interrupt armed. This resulted
> in the ACPI device PM system placing the device into D3Cold, and thus
> cutting power to the device. With this change we will now query the
> _S0W method to figure out the appropriate wake capable D-state.
>
> Signed-off-by: Raul E Rangel <rrangel@...omium.org>
> ---
>
> Changes in v5:
> - Go back to using adev->wakeup.flags.valid to keep the diff cleaner
> - Fix a typo in comment
>
>  drivers/acpi/device_pm.c | 19 +++++++++++++++++--
>  1 file changed, 17 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
> index 9dce1245689ca2..3111fc426e04fd 100644
> --- a/drivers/acpi/device_pm.c
> +++ b/drivers/acpi/device_pm.c
> @@ -681,8 +681,23 @@ static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
>                 d_min = ret;
>                 wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
>                         && adev->wakeup.sleep_state >= target_state;
> -       } else {
> -               wakeup = adev->wakeup.flags.valid;
> +       } else if (adev->wakeup.flags.valid) {
> +               /* ACPI GPE specified in _PRW. */
> +               wakeup = true;

I would retain the "else" clause as it was and just add a new "else
if" one before it.

> +       } else if (device_may_wakeup(dev) && dev->power.wakeirq) {
> +               /*
> +                * The ACPI subsystem doesn't manage the wake bit for IRQs
> +                * defined with ExclusiveAndWake and SharedAndWake. Instead we
> +                * expect them to be managed via the PM subsystem. Drivers
> +                * should call dev_pm_set_wake_irq to register an IRQ as a wake
> +                * source.
> +                *
> +                * If a device has a wake IRQ attached we need to check the
> +                * _S0W method to get the correct wake D-state. Otherwise we
> +                * end up putting the device into D3Cold which will more than
> +                * likely disable wake functionality.
> +                */
> +               wakeup = true;
>         }
>
>         /*
> --