gpio: acpi: Ignore -EPROBE_DEFER for unselected gpioints

When acpi_dev_gpio_irq_get gets called with an index of say 2, it should
not care if acpi_get_gpiod for index 0 or 1 returns -EPROBE_DEFER.

This allows drivers which request a gpioint with index > 0 to function
if there is no gpiochip driver (loaded) for gpioints with a lower index.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpiolib-acpi.c

@@ -684,20 +684,24 @@ int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index)
 {
 	int idx, i;
 	unsigned int irq_flags;
-	int ret = -ENOENT;
 
 	for (i = 0, idx = 0; idx <= index; i++) {
 		struct acpi_gpio_info info;
 		struct gpio_desc *desc;
 
 		desc = acpi_get_gpiod_by_index(adev, NULL, i, &info);
-		if (IS_ERR(desc)) {
-			ret = PTR_ERR(desc);
-			break;
-		}
+
+		/* Ignore -EPROBE_DEFER, it only matters if idx matches */
+		if (IS_ERR(desc) && PTR_ERR(desc) != -EPROBE_DEFER)
+			return PTR_ERR(desc);
+
 		if (info.gpioint && idx++ == index) {
-			int irq = gpiod_to_irq(desc);
+			int irq;
+
+			if (IS_ERR(desc))
+				return PTR_ERR(desc);
 
+			irq = gpiod_to_irq(desc);
 			if (irq < 0)
 				return irq;
 
@@ -713,7 +717,7 @@ int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index)
 		}
 
 	}
-	return ret;
+	return -ENOENT;
 }
 EXPORT_SYMBOL_GPL(acpi_dev_gpio_irq_get);