gpio: mt7621: pass mediatek_gpio_bank_probe() failure up the stack

[ Upstream commit a109c2dbb571b10bb9969285b646f57309c98251 ]

The error cases of mediatek_gpio_bank_probe() would go unnoticed (except
for the dev_err() messages). The probe function should return an error
if one of the banks failed to initialize properly indicated by
not returning non-0.

Fixes: 4ba9c3afda41 ("gpio: mt7621: Add a driver for MT7621")
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Acked-by: Sean Wang <sean.wang@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/gpio/gpio-mt7621.c

@@ -297,6 +297,7 @@ mediatek_gpio_probe(struct platform_device *pdev)
 	struct device_node *np = dev->of_node;
 	struct mtk *mtk;
 	int i;
+	int ret;
 
 	mtk = devm_kzalloc(dev, sizeof(*mtk), GFP_KERNEL);
 	if (!mtk)
@@ -311,8 +312,11 @@ mediatek_gpio_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, mtk);
 	mediatek_gpio_irq_chip.name = dev_name(dev);
 
-	for (i = 0; i < MTK_BANK_CNT; i++)
-		mediatek_gpio_bank_probe(dev, np, i);
+	for (i = 0; i < MTK_BANK_CNT; i++) {
+		ret = mediatek_gpio_bank_probe(dev, np, i);
+		if (ret)
+			return ret;
+	}
 
 	return 0;
 }