ACPI: x86: Introduce an acpi_quirk_skip_gpio_event_handlers() helper

x86 ACPI boards which ship with only Android as their factory image usually
have pretty broken ACPI tables, relying on everything being hardcoded in
the factory kernel image and often disabling parts of the ACPI enumeration
kernel code to avoid the broken tables causing issues.

Part of this broken ACPI code is that sometimes these boards have _AEI
ACPI GPIO event handlers which are broken.

So far this has been dealt with in the platform/x86/x86-android-tablets.c
module, which contains various workarounds for these devices, by it calling
acpi_gpiochip_free_interrupts() on gpiochip-s with troublesome handlers to
disable the handlers.

But in some cases this is too late, if the handlers are of the edge type
then gpiolib-acpi.c's code will already have run them at boot.
This can cause issues such as GPIOs ending up as owned by "ACPI:OpRegion",
making them unavailable for drivers which actually need them.

Boards with these broken ACPI tables are already listed in
drivers/acpi/x86/utils.c for e.g. acpi_quirk_skip_i2c_client_enumeration().
Extend the quirks mechanism for a new acpi_quirk_skip_gpio_event_handlers()
helper, this re-uses the DMI-ids rather then having to duplicate the same
DMI table in gpiolib-acpi.c .

Also add the new ACPI_QUIRK_SKIP_GPIO_EVENT_HANDLERS quirk to existing
boards with troublesome ACPI gpio event handlers, so that the current
acpi_gpiochip_free_interrupts() hack can be removed from
x86-android-tablets.c .

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@rjwysocki.net>

0 files changed, 0 insertions, 0 deletions