From bdfd6ab8fdccd8b138837efff66f4a1911496378 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Thu, 25 Nov 2021 21:30:10 +0100 Subject: [PATCH] gpiolib: acpi: Do not set the IRQ type if the IRQ is already in use If the IRQ is already in use, then acpi_dev_gpio_irq_get_by() really should not change the type underneath the current owner. I specifically hit an issue with this an a Chuwi Hi8 Super (CWI509) Bay Trail tablet, when the Boot OS selection in the BIOS is set to Android. In this case _STA for a MAX17047 ACPI I2C device wrongly returns 0xf and the _CRS resources for this device include a GpioInt pointing to a GPIO already in use by an _AEI handler, with a different type then specified in the _CRS for the MAX17047 device. Leading to the acpi_dev_gpio_irq_get() call done by the i2c-core-acpi.c code changing the type breaking the _AEI handler. Now this clearly is a bug in the DSDT of this tablet (in Android mode), but in general calling irq_set_irq_type() on an IRQ which already is in use seems like a bad idea. Signed-off-by: Hans de Goede Signed-off-by: Andy Shevchenko --- drivers/gpio/gpiolib-acpi.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c index 7dd0484b89c6..02b06e69b50b 100644 --- a/drivers/gpio/gpiolib-acpi.c +++ b/drivers/gpio/gpiolib-acpi.c @@ -1044,10 +1044,17 @@ int acpi_dev_gpio_irq_get_by(struct acpi_device *adev, const char *name, int ind irq_flags = acpi_dev_get_irq_type(info.triggering, info.polarity); - /* Set type if specified and different than the current one */ - if (irq_flags != IRQ_TYPE_NONE && - irq_flags != irq_get_trigger_type(irq)) - irq_set_irq_type(irq, irq_flags); + /* + * If the IRQ is not already in use then set type + * if specified and different than the current one. + */ + if (can_request_irq(irq, irq_flags)) { + if (irq_flags != IRQ_TYPE_NONE && + irq_flags != irq_get_trigger_type(irq)) + irq_set_irq_type(irq, irq_flags); + } else { + dev_dbg(&adev->dev, "IRQ %d already in use\n", irq); + } return irq; } -- 2.11.0