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gpio: mvebu: convert to noirq suspend/resume to prevent interrupt storm on resume

PATCH In review Rosen Penev 2 participants 2 messages Sep 29 GPIO

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#0 lore raw

PATCH v3 1/1 gpio: mvebu: convert to noirq suspend/resume to prevent interrupt storm on resume

The driver uses the legacy .suspend/.resume callbacks, but sets IRQCHIP_MASK_ON_SUSPEND on the irq_chip. During resume, the PM core runs dpm_resume_noirq() first, which calls irq_pm_resume() to unmask interrupts, and only then runs dpm_resume() which invokes the driver's .resume callback to restore GPIO registers (GPIO_IN_POL, GPIO_IO_CONF, mask registers).

This ordering means interrupts are unmasked while the hardware is still in its reset state, potentially with incorrect polarities, causing spurious level-triggered interrupts before local IRQs are re-enabled.

Convert the driver from legacy .suspend/.resume callbacks to noirq callbacks via dev_pm_ops. The noirq phase runs before resume_device_irqs() on resume and after suspend_device_irqs() on suspend, ensuring GPIO registers are restored before interrupts are unmasked.

Assisted-by LLM

---
v3: use NOIRQ_SYSTEM_SLEEP_PM_OPS instead.
v2: add __maybe_unused to fix compilation

 drivers/gpio/gpio-mvebu.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)
drivers/gpio/gpio-mvebu.c +9 -6
index 267e6d5bacd0..27894acf8d34 100644
@@ -994,9 +994,9 @@ static const struct of_device_id mvebu_gpio_of_match[] = {
 	},
 };
 
-static int mvebu_gpio_suspend(struct platform_device *pdev, pm_message_t state)
+static int mvebu_gpio_suspend(struct device *dev)
 {
-	struct mvebu_gpio_chip *mvchip = platform_get_drvdata(pdev);
+	struct mvebu_gpio_chip *mvchip = dev_get_drvdata(dev);
 	int i;
 
 	regmap_read(mvchip->regs, GPIO_OUT_OFF + mvchip->offset,
@@ -1046,9 +1046,9 @@ static int mvebu_gpio_suspend(struct platform_device *pdev, pm_message_t state)
 	return 0;
 }
 
-static int mvebu_gpio_resume(struct platform_device *pdev)
+static int mvebu_gpio_resume(struct device *dev)
 {
-	struct mvebu_gpio_chip *mvchip = platform_get_drvdata(pdev);
+	struct mvebu_gpio_chip *mvchip = dev_get_drvdata(dev);
 	u32 edge_cache = ~0U, level_cache = ~0U;
 	unsigned long flags;
 	int i;
@@ -1369,13 +1369,16 @@ static int mvebu_gpio_probe(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct dev_pm_ops mvebu_gpio_pm_ops = {
+	NOIRQ_SYSTEM_SLEEP_PM_OPS(mvebu_gpio_suspend, mvebu_gpio_resume)
+};
+
 static struct platform_driver mvebu_gpio_driver = {
 	.driver		= {
 		.name		= "mvebu-gpio",
 		.of_match_table = mvebu_gpio_of_match,
+		.pm		= pm_sleep_ptr(&mvebu_gpio_pm_ops),
 	},
 	.probe		= mvebu_gpio_probe,
-	.suspend        = mvebu_gpio_suspend,
-	.resume         = mvebu_gpio_resume,
 };
 builtin_platform_driver(mvebu_gpio_driver);
Signature · 1 line
2.55.0
#1 lore raw
Quoted 11 lines · Rosen Penev

The driver uses the legacy .suspend/.resume callbacks, but sets IRQCHIP_MASK_ON_SUSPEND on the irq_chip. During resume, the PM core runs dpm_resume_noirq() first, which calls irq_pm_resume() to unmask interrupts, and only then runs dpm_resume() which invokes the driver's .resume callback to restore GPIO registers (GPIO_IN_POL, GPIO_IO_CONF, mask registers).

This ordering means interrupts are unmasked while the hardware is still in its reset state, potentially with incorrect polarities, causing spurious level-triggered interrupts before local IRQs are re-enabled.

Quoted 8 lines

Convert the driver from legacy .suspend/.resume callbacks to noirq callbacks via dev_pm_ops. The noirq phase runs before resume_device_irqs() on resume and after suspend_device_irqs() on suspend, ensuring GPIO registers are restored before interrupts are unmasked.

Assisted-by LLM

---

This doesn't apply on top of current gpio/for-next. Either rebase and and resend or - if there are dependencies from current upstream - mention them in the cover letter.

Bart