Fujitsu extra buttons not working on S6010

Dear experts,

following the bug report on bugzilla

https://bugzilla.kernel.org/show_bug.cgi?id=84381

the extra buttons (ACPI-driven buttons) on the R31 laptop do not work since kernel 3.17.0. Kernel 3.16.x worked fine. The same problem (or at least a very similar problem) exists on the Fujitsu-S6010 laptop.

After debugging for a while, the culprit seems to be in arch/x86/kernel/acpi/boot.c, in specific in acpi_gsi_to_irq(). The following changes fix this problem for at least the S6010:

static unsigned int gsi_to_irq(unsigned int gsi)

{
	unsigned int irq = gsi + NR_IRQS_LEGACY;
	unsigned int i;

	for (i = 0; i<  NR_IRQS_LEGACY; i++) {
		if (isa_irq_to_gsi[i] == gsi) {
			return i;
		}
	}

	/* Provide an identity mapping of gsi == irq
	 * except on truly weird platforms that have
	 * non isa irqs in the first 16 gsis.
	 */
	if (gsi>= NR_IRQS_LEGACY)
		irq = gsi;
	else
		irq = gsi_top + gsi;

	return irq;
}

/* THOR: Experimental end */

int acpi_gsi_to_irq(u32 gsi, unsigned int *irqp)

{
	int irq = mp_map_gsi_to_irq(gsi, IOAPIC_MAP_ALLOC | IOAPIC_MAP_CHECK);

	if (irq>= 0) {
		*irqp = irq;
		return 0;
	}

	/* THOR: Experimental start */
	irq = gsi_to_irq(gsi);
	if (irq>= 0) {
	  *irqp = irq;
	  return 0;
	}
	/* THOR Experimental end */

	return -1;
}

Whether this works on the R31 is yet to be determined.

It would be great if you could integrate this patch into the next kernel release to get the laptop buttons working again. With this patch, both the ACPI-buttons as well as the backlight control device in sys/class/backlight/fujitsu-laptop works.

Thanks,
Thomas