Commit 009d6d9f authored Nov 25, 2021 by Hans de Goede Committed by Greg Kroah-Hartman Jan 27, 2022

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@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 50ad94f8

drivers/gpio/gpiolib-acpi.c

+11 −4

Original line number	Diff line number	Diff line
		@@ -953,10 +953,17 @@ int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index)
		irq_flags = acpi_dev_get_irq_type(info.triggering,
		info.polarity);

		/* Set type if specified and different than the current one */
		/*
		* 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;
		}