This is a note to let you know that I've just added the patch titled gpiolib: acpi: Do not set the IRQ type if the IRQ is already in use to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: gpiolib-acpi-do-not-set-the-irq-type-if-the-irq-is-a.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 2942e57eb56874541a047fae40bb5526955a81ce Author: Hans de Goede <hdegoede@xxxxxxxxxx> Date: Thu Nov 25 21:30:10 2021 +0100 gpiolib: acpi: Do not set the IRQ type if the IRQ is already in use [ Upstream commit bdfd6ab8fdccd8b138837efff66f4a1911496378 ] 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 <hdegoede@xxxxxxxxxx> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c index 47712b6903b51..d040c72fea582 100644 --- a/drivers/gpio/gpiolib-acpi.c +++ b/drivers/gpio/gpiolib-acpi.c @@ -1059,10 +1059,17 @@ 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; }