Re: [PATCH v5 2/2] pinctrl: amd: Fix wakeups when IRQ is shared with SCI

From: Basavaraj Natikar
Date: Thu Oct 28 2021 - 10:58:35 EST



On 10/28/2021 8:15 PM, Mario Limonciello wrote:
> On some Lenovo AMD Gen2 platforms the IRQ for the SCI and pinctrl drivers
> are shared. Due to how the s2idle loop handling works, this case needs
> an extra explicit check whether the interrupt was caused by SCI or by
> the GPIO controller.
>
> To fix this rework the existing IRQ handler function to function as a
> checker and an IRQ handler depending on the calling arguments.
>
> Cc: stable@xxxxxxxxxx
> BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1738
> Reported-by: Joerie de Gram <j.de.gram@xxxxxxxxx>
> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> ---
> Note:
> This is *possibly* a fix from fdde0ff8590b, 56b991849009 or other
> changes in the acpi_s2idle_wake handling, but AMD didn't support
> s2idle across the kernel widely until 5.14 or later. This is the
> reason for lack of a fixes tag.
> Changes from v4->v5:
> * Correct debugging statement that was obfuscated by kernel %p behavior.
> * Instead show actual GPIO number, which is much more useful for debugging
> * Target to stable as well
> Changes from v3->v4:
> * Adjust to reverse xmas for newly added variable
> * Add a debugging line to show the values in the register that caused system
> wake to allow for debugging of spurious wakeups
> Changes from v2->v3:
> * Add new precursor patch for fixing missing ACPI function stubs
> * Add __maybe_unused for unused function when set with COMPILE_TEST
> Changes from v1->v2:
> * drop Kconfig changes to drop COMPILE_TEST, instead #ifdef CONFIG_ACPI
> * fix a logic error during wakeup
> * Use IRQ_RETVAL()
> drivers/pinctrl/pinctrl-amd.c | 31 ++++++++++++++++++++++++++++---
> 1 file changed, 28 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pinctrl/pinctrl-amd.c b/drivers/pinctrl/pinctrl-amd.c
> index d19974aceb2e..83fbcdad0904 100644
> --- a/drivers/pinctrl/pinctrl-amd.c
> +++ b/drivers/pinctrl/pinctrl-amd.c
> @@ -598,14 +598,14 @@ static struct irq_chip amd_gpio_irqchip = {
>
> #define PIN_IRQ_PENDING (BIT(INTERRUPT_STS_OFF) | BIT(WAKE_STS_OFF))
>
> -static irqreturn_t amd_gpio_irq_handler(int irq, void *dev_id)
> +static bool _amd_gpio_irq_handler(int irq, void *dev_id)
> {
> struct amd_gpio *gpio_dev = dev_id;
> struct gpio_chip *gc = &gpio_dev->gc;
> - irqreturn_t ret = IRQ_NONE;
> unsigned int i, irqnr;
> unsigned long flags;
> u32 __iomem *regs;
> + bool ret = false;
> u32 regval;
> u64 status, mask;
>
> @@ -627,6 +627,16 @@ static irqreturn_t 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);
> + /* called from resume context on a shared IRQ, just
> + * checking wake source.
> + */
> + if (irq < 0 && (regval & BIT(WAKE_STS_OFF))) {
> + dev_dbg(&gpio_dev->pdev->dev,
> + "Waking due to GPIO %ld: 0x%x",
> + regs + i - ((u32 __iomem *)gpio_dev->base), regval);
> + return true;
> + }
> +
> if (!(regval & PIN_IRQ_PENDING) ||
> !(regval & BIT(INTERRUPT_MASK_OFF)))
> continue;
> @@ -652,9 +662,12 @@ static irqreturn_t amd_gpio_irq_handler(int irq, void *dev_id)
> }
> writel(regval, regs + i);
> raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);
> - ret = IRQ_HANDLED;
> + ret = true;
> }
> }
> + /* called from resume context on shared IRQ but didn't cause wake */
> + if (irq < 0)
> + return false;
>
> /* Signal EOI to the GPIO unit */
> raw_spin_lock_irqsave(&gpio_dev->lock, flags);
> @@ -666,6 +679,16 @@ static irqreturn_t amd_gpio_irq_handler(int irq, void *dev_id)
> return ret;
> }
>
> +static irqreturn_t amd_gpio_irq_handler(int irq, void *dev_id)
> +{
> + return IRQ_RETVAL(_amd_gpio_irq_handler(irq, dev_id));
> +}
> +
> +static bool __maybe_unused amd_gpio_check_wake(void *dev_id)
> +{
> + return _amd_gpio_irq_handler(-1, dev_id);
> +}
> +
> static int amd_get_groups_count(struct pinctrl_dev *pctldev)
> {
> struct amd_gpio *gpio_dev = pinctrl_dev_get_drvdata(pctldev);
> @@ -1004,6 +1027,7 @@ static int amd_gpio_probe(struct platform_device *pdev)
> goto out2;
>
> platform_set_drvdata(pdev, gpio_dev);
> + acpi_register_wakeup_handler(gpio_dev->irq, amd_gpio_check_wake, gpio_dev);
>
> dev_dbg(&pdev->dev, "amd gpio driver loaded\n");
> return ret;
> @@ -1021,6 +1045,7 @@ static int amd_gpio_remove(struct platform_device *pdev)
> gpio_dev = platform_get_drvdata(pdev);
>
> gpiochip_remove(&gpio_dev->gc);
> + acpi_unregister_wakeup_handler(amd_gpio_check_wake, gpio_dev);
>
> return 0;
> }

Looks good to me

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


Thanks,
Basavaraj