[PATCH] gpio: ath79: Check for error irq

[Jiasheng Jiang <jiasheng@xxxxxxxxxxx>]

For the possible failure of the platform_get_irq(), the returned irq
could be error number and will finally cause the failure of the
request_irq().
Consider that platform_get_irq() can now in certain cases return
-EPROBE_DEFER, and the consequences of letting request_irq() effectively
convert that into -EINVAL, even at probe time rather than later on.
So it might be better to check just now.

Fixes: 1d473c2cb9fe ("MIPS: ath79: Move the GPIO driver to drivers/gpio")
Signed-off-by: Jiasheng Jiang <jiasheng@xxxxxxxxxxx>
---
 drivers/gpio/gpio-ath79.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-ath79.c b/drivers/gpio/gpio-ath79.c
index 678ddd375891..11f49998e56a 100644
--- a/drivers/gpio/gpio-ath79.c
+++ b/drivers/gpio/gpio-ath79.c
@@ -285,7 +285,13 @@ static int ath79_gpio_probe(struct platform_device *pdev)
 					     GFP_KERNEL);
 		if (!girq->parents)
 			return -ENOMEM;
-		girq->parents[0] = platform_get_irq(pdev, 0);
+
+		err = platform_get_irq(pdev, 0);
+		if (err < 0)
+			return err;
+
+		girq->parents[0] = err;
+
 		girq->default_type = IRQ_TYPE_NONE;
 		girq->handler = handle_simple_irq;
 	}
-- 
2.25.1