Re: [PATCH 2/5] platform/x86: x86-android-tablets: Fix EBUSY error when requesting IOAPIC IRQs

[Andy Shevchenko <andriy.shevchenko@intel.com>]

On Wed, Feb 23, 2022 at 02:31:50PM +0100, Hans de Goede wrote:
> Sometimes IRQs used by GPIOs in direct-IRQ mode are already registered
> because they are used as ACPI "Interrupt () {}" resource for one of the
> many bogus I2C devices present in the broken DSDTs of Android x86 tablets.
> 
> This is an issue if the existing (bogus) ACPI resource uses different
> trigger settings then what is being requested, leading to an -EBUSY
> error return of acpi_register_gsi().
> 
> Fix this by calling acpi_unregister_gsi() first, so that
> the acpi_register_gsi() is allowed to change the trigger settings.
> 
> In cases where the GSI has not been registered yet
> the acpi_unregister_gsi() is a no-op.

...

>  	case X86_ACPI_IRQ_TYPE_APIC:
> +		/*
> +		 * The DSDT may already reference the GSI in a device skipped by
> +		 * acpi_quirk_skip_i2c_client_enumeration(). Unregister the GSI
> +		 * to avoid EBUSY errors in this case.
> +		 */
> +		acpi_unregister_gsi(data->index);

Perhaps a warning (or at least debug) message?

-- 
With Best Regards,
Andy Shevchenko