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 <hdegoede@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
This commit is contained in:
Hans de Goede 2021-11-25 21:30:10 +01:00 committed by Andy Shevchenko
parent 2ff64a84bb
commit bdfd6ab8fd

View file

@ -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;
}