[PATCH] gpio: thunderx: fix irq_request_resources

[Tim Harvey <tharvey@gateworks.com>]

If there are no parent resources do not call irq_chip_request_resources_parent
at all as this will return an error.

This resolves a regression where devices using a thunderx gpio as an interrupt
would fail probing.

Fixes: 0d04d0c ("gpio: thunderx: Use the default parent apis for {request,release}_resources")
Signed-off-by: Tim Harvey <tharvey@gateworks.com>
---
 drivers/gpio/gpio-thunderx.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/gpio/gpio-thunderx.c b/drivers/gpio/gpio-thunderx.c
index 4627704..f84b9b1 100644
--- a/drivers/gpio/gpio-thunderx.c
+++ b/drivers/gpio/gpio-thunderx.c
@@ -366,15 +366,18 @@ static int thunderx_gpio_irq_request_resources(struct irq_data *data)
 {
 	struct thunderx_line *txline = irq_data_get_irq_chip_data(data);
 	struct thunderx_gpio *txgpio = txline->txgpio;
+	struct irq_data *parent_data = data->parent_data;
 	int r;
 
 	r = gpiochip_lock_as_irq(&txgpio->chip, txline->line);
 	if (r)
 		return r;
 
-	r = irq_chip_request_resources_parent(data);
-	if (r)
-		gpiochip_unlock_as_irq(&txgpio->chip, txline->line);
+	if (parent_data && parent_data->chip->irq_request_resources) {
+		r = irq_chip_request_resources_parent(data);
+		if (r)
+			gpiochip_unlock_as_irq(&txgpio->chip, txline->line);
+	}
 
 	return r;
 }
-- 
2.7.4