diff options
| -rw-r--r-- | drivers/gpio/gpiolib-acpi-core.c | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/drivers/gpio/gpiolib-acpi-core.c b/drivers/gpio/gpiolib-acpi-core.c index fbd6945726bf..1a762a2988b7 100644 --- a/drivers/gpio/gpiolib-acpi-core.c +++ b/drivers/gpio/gpiolib-acpi-core.c @@ -229,12 +229,23 @@ 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); } } |