From 3bb62e3f99a557d257e5f5a803200051b7de3afa Mon Sep 17 00:00:00 2001 From: Mario Limonciello Date: Tue, 28 Apr 2026 21:52:39 -0500 Subject: [PATCH] gpiolib: acpi: Only trigger ActiveBoth interrupts on boot Commit ca876c7483b6 ("gpiolib-acpi: make sure we trigger edge events at least once on boot") introduced logic to trigger edge-based GPIO interrupts during initialization to ensure proper initial state setup when firmware doesn't initialize it. However, according to the Microsoft GPIO documentation, triggering GPIO interrupts during initialization should only happen for interrupts marked as ActiveBoth (both IRQF_TRIGGER_RISING and IRQF_TRIGGER_FALLING) and only when the associated GPIO line is already asserted (logic level low). The current implementation incorrectly triggers: 1. Any edge-triggered interrupt (RISING-only or FALLING-only) 2. RISING interrupts when value is high and FALLING when value is low This causes problems at bootup for single-edge interrupts that don't follow the ActiveBoth pattern. Fix this by: - Only triggering when BOTH rising and falling edges are configured - Only triggering when the GPIO line is asserted (value == 0) Reported-by: Francesco Lauritano Closes: https://lore.kernel.org/all/6iFCwGH2vssb7NRUTWGpkubGMNbgIlBHSz40z8ZsezjxngXpoiiRiJaijviNvhiDAGIr43bfUmdxLmxYoHDjyft4DgwFc3Pnu5hzPguTa0s=@protonmail.com/ Tested-by: Marco Scardovi Fixes: ca876c7483b69 ("gpiolib-acpi: make sure we trigger edge events at least once on boot") Link: https://learn.microsoft.com/en-us/windows-hardware/drivers/bringup/general-purpose-i-o--gpio- Suggested-by: Armin Wolf Signed-off-by: Mario Limonciello Reviewed-by: Mika Westerberg Reviewed-by: Hans de Goede Signed-off-by: Andy Shevchenko --- drivers/gpio/gpiolib-acpi-core.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/drivers/gpio/gpiolib-acpi-core.c b/drivers/gpio/gpiolib-acpi-core.c index 09f860200a05..eb8a40cfb7a9 100644 --- a/drivers/gpio/gpiolib-acpi-core.c +++ b/drivers/gpio/gpiolib-acpi-core.c @@ -233,12 +233,23 @@ static void acpi_gpiochip_request_irq(struct acpi_gpio_chip *acpi_gpio, event->irq_requested = true; - /* Make sure we trigger the initial state of edge-triggered IRQs */ + /* + * Make sure we trigger the initial state of ActiveBoth IRQs. + * + * According to the Microsoft GPIO documentation, triggering GPIO + * interrupts marked as ActiveBoth during initialization is correct + * as long as the associated GPIO line is already "asserted" + * (logic level low). We should not trigger edge-based GPIO + * interrupts not marked as ActiveBoth. + * + * See: https://learn.microsoft.com/en-us/windows-hardware/drivers/bringup/general-purpose-i-o--gpio- + * Section: "GPIO controllers and ActiveBoth interrupts" + */ if (acpi_gpio_need_run_edge_events_on_boot() && - (event->irqflags & (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING))) { + ((event->irqflags & (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)) == + (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING))) { value = gpiod_get_raw_value_cansleep(event->desc); - if (((event->irqflags & IRQF_TRIGGER_RISING) && value == 1) || - ((event->irqflags & IRQF_TRIGGER_FALLING) && value == 0)) + if (value == 0) event->handler(event->irq, event); } }