[See http://lists.ozlabs.org/pipermail/linuxppc-dev/2010-October/086424.html
and followups. Part of the commit message is directly copied from that.]
Commit 
540c6c392f01887dcc96bef0a41e63e6c1334f01 tries to find i8042 IRQs in
the device-tree but doesn't fall back to the old hardcoded 1 and 12 in all
failure cases.
Specifically, the case where the device-tree contains nothing matching
pnpPNP,303 or pnpPNP,f03 doesn't seem to be handled well. It sort of falls
through to the old code, but leaves the IRQs set to 0.
Signed-off-by: Gabriel Paubert <paubert@iram.es>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
 
                 * name instead */
                if (!np)
                        np = of_find_node_by_name(NULL, "8042");
+               if (np) {
+                       of_i8042_kbd_irq = 1;
+                       of_i8042_aux_irq = 12;
+               }
                break;
        case FDC_BASE: /* FDC1 */
                np = of_find_node_by_type(NULL, "fdc");