linux-kernel - Re: [PATCH 1/1] pinctrl: amd: Add dynamic debugging for active GPIOs

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Date:   Thu, 13 Oct 2022 12:08:30 +0530
From:   Basavaraj Natikar <bnatikar@....com>
To:     Mario Limonciello <mario.limonciello@....com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Basavaraj Natikar <Basavaraj.Natikar@....com>,
        Shyam Sundar S K <Shyam-sundar.S-k@....com>
Cc:     Mark Pearson <mpearson@...ovo.com>,
        Pananchikkal Renjith <Renjith.Pananchikkal@....com>,
        Kai-Heng Feng <kai.heng.feng@...onical.com>,
        linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/1] pinctrl: amd: Add dynamic debugging for active GPIOs


On 10/13/2022 3:40 AM, Mario Limonciello wrote:
> Some laptops have been reported to wake up from s2idle when plugging
> in the AC adapter or by closing the lid.  This is a surprising
> behavior that is further clarified by commit cb3e7d624c3ff ("PM:
> wakeup: Add extra debugging statement for multiple active IRQs").
>
> With that commit in place the following interaction can be seen
> when the lid is closed:
>
> [   28.946038] PM: suspend-to-idle
> [   28.946083] ACPI: EC: ACPI EC GPE status set
> [   28.946101] ACPI: PM: Rearming ACPI SCI for wakeup
> [   28.950152] Timekeeping suspended for 3.320 seconds
> [   28.950152] PM: Triggering wakeup from IRQ 9
> [   28.950152] ACPI: EC: ACPI EC GPE status set
> [   28.950152] ACPI: EC: ACPI EC GPE dispatched
> [   28.995057] ACPI: EC: ACPI EC work flushed
> [   28.995075] ACPI: PM: Rearming ACPI SCI for wakeup
> [   28.995131] PM: Triggering wakeup from IRQ 9
> [   28.995271] ACPI: EC: ACPI EC GPE status set
> [   28.995291] ACPI: EC: ACPI EC GPE dispatched
> [   29.098556] ACPI: EC: ACPI EC work flushed
> [   29.207020] ACPI: EC: ACPI EC work flushed
> [   29.207037] ACPI: PM: Rearming ACPI SCI for wakeup
> [   29.211095] Timekeeping suspended for 0.739 seconds
> [   29.211095] PM: Triggering wakeup from IRQ 9
> [   29.211079] PM: Triggering wakeup from IRQ 7
> [   29.211095] ACPI: PM: ACPI non-EC GPE wakeup
> [   29.211095] PM: resume from suspend-to-idle
>
> * IRQ9 on this laptop is used for the ACPI SCI.
> * IRQ7 on this laptop is used for the GPIO controller.
>
> What has occurred is when the lid was closed the EC woke up the
> SoC from it's deepest sleep state and the kernel's s2idle loop
> processed all EC events.  When it was finished processing EC events,
> it checked for any other reasons to wake (break the s2idle loop).
>
> The IRQ for the GPIO controller was active so the loop broke, and
> then this IRQ was processed.  This is not a kernel bug but it is
> certainly a surprising behavior, and to better debug it we should
> have a dynamic debugging message that we can enact to catch it.
>
> Signed-off-by: Mario Limonciello <mario.limonciello@....com>
> ---
>  drivers/pinctrl/pinctrl-amd.c | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/pinctrl/pinctrl-amd.c b/drivers/pinctrl/pinctrl-amd.c
> index 4691a33bc374f..8378b4115ec0d 100644
> --- a/drivers/pinctrl/pinctrl-amd.c
> +++ b/drivers/pinctrl/pinctrl-amd.c
> @@ -628,13 +628,16 @@ static bool do_amd_gpio_irq_handler(int irq, void *dev_id)
>  		/* Each status bit covers four pins */
>  		for (i = 0; i < 4; i++) {
>  			regval = readl(regs + i);
> -			/* caused wake on resume context for shared IRQ */
> -			if (irq < 0 && (regval & BIT(WAKE_STS_OFF))) {
> +
> +			if (regval & BIT(WAKE_STS_OFF) ||
> +			    regval & BIT(INTERRUPT_STS_OFF))

Above if can be simplified as "if (regval & PIN_IRQ_PENDING)"

with that change,

Acked-by:  Basavaraj Natikar <Basavaraj.Natikar@....com>


Thanks,
--
Basavaraj

>  				dev_dbg(&gpio_dev->pdev->dev,
> -					"Waking due to GPIO %d: 0x%x",
> +					"GPIO %d is active: 0x%x",
>  					irqnr + i, regval);
> +
> +			/* caused wake on resume context for shared IRQ */
> +			if (irq < 0 && (regval & BIT(WAKE_STS_OFF)))
>  				return true;
> -			}
>  
>  			if (!(regval & PIN_IRQ_PENDING) ||
>  			    !(regval & BIT(INTERRUPT_MASK_OFF)))