Re: [PATCH] gpiolib: acpi: Do not set the IRQ type if the IRQ is already in use
From: Andy Shevchenko <hidden>
Date: 2021-11-23 09:36:18
Also in:
linux-acpi
On Mon, Nov 22, 2021 at 11:04:16PM +0100, Hans de Goede wrote:
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.
I'm fine with the change, one comment below, though.
quoted hunk ↗ jump to hunk
Signed-off-by: Hans de Goede <redacted> --- drivers/gpio/gpiolib-acpi.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c index 985e8589c58b..24cd86bf2c4c 100644 --- a/drivers/gpio/gpiolib-acpi.c +++ b/drivers/gpio/gpiolib-acpi.c@@ -1056,8 +1056,12 @@ 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 && + /* + * 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) && + irq_flags != IRQ_TYPE_NONE && irq_flags != irq_get_trigger_type(irq)) irq_set_irq_type(irq, irq_flags);
What about issuing a debug (?) message
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(..., FW_BUG "IRQ %d already in use\n", irq);
}
?
--
With Best Regards,
Andy Shevchenko