linux-imx

gpiolib-acpi: Only defer request_irq for GpioInt ACPI event handlers

Commit 78d3a92edbfb ("gpiolib-acpi: Register GpioInt ACPI event handlers
from a late_initcall") deferred the entire acpi_gpiochip_request_interrupt
call for each event resource.

This means it also delays the gpiochip_request_own_desc(..., "ACPI:Event")
call. This is a problem if some AML code reads the GPIO pin before we
run the deferred acpi_gpiochip_request_interrupt, because in that case
acpi_gpio_adr_space_handler() will already have called
gpiochip_request_own_desc(..., "ACPI:OpRegion") causing the call from
acpi_gpiochip_request_interrupt to fail with -EBUSY and we will fail to
register an event handler.

acpi_gpio_adr_space_handler is prepared for acpi_gpiochip_request_interrupt
already having claimed the pin, but the other way around does not work.

One example of a problem this causes, is the event handler for the OTG
ID pin on a Prowise PT301 tablet not registering, keeping the port stuck
in whatever mode it was in during boot and e.g. only allowing charging
after a reboot.

This commit fixes this by only deferring the request_irq call and the
initial run of edge-triggered IRQs instead of deferring all of
acpi_gpiochip_request_interrupt.

Cc: stable@vger.kernel.org
Fixes: 78d3a92edbfb ("gpiolib-acpi: Register GpioInt ACPI event ...")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>