of_irq_get() may return  any negative error number as well as 0 on failure,
while the driver only checks for -EPROBE_DEFER, blithely continuing with
the call to gpiochip_set_chained_irqchip() -- that function expects the
parent IRQ as *unsigned int*, so would probably do nothing  when a large
IRQ number resulting from a conversion of a negative error number is passed
to it, however passing 0 would probably work but the driver won't receive
valid GPIO bank interrupts.
Check for 'ret <= 0' instead and return -ENXIO from the driver's probe iff
of_irq_get() returned 0.
Fixes: f9367793293d ("pinctrl: sirf: add sirf atlas7 pinctrl and gpio support")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
 
                /* Get interrupt number from DTS */
                ret = of_irq_get(np, idx);
-               if (ret == -EPROBE_DEFER) {
+               if (ret <= 0) {
                        dev_err(&pdev->dev,
                                "Unable to find IRQ number. ret=%d\n", ret);
+                       if (!ret)
+                               ret = -ENXIO;
                        goto failed;
                }
                bank->irq = ret;