[PATCH 4.9 042/206] usb: return error code when platform_get_irq fails

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Pan Bian <bianpan2016@xxxxxxx>

commit 28bedb5ae463b9f7e5195cbc93f1795e374bdef8 upstream.

In function xhci_mtk_probe(), variable ret takes the return value. Its
value should be negative on failures. However, when the call to function
platform_get_irq() fails, it does not set the error code, and 0 will be
returned. 0 indicates no error. As a result, the callers of function
xhci_mtk_probe() will not be able to detect the error. This patch fixes
the bug by assigning the return value of platform_get_irq() to variable
ret if it fails.

Signed-off-by: Pan Bian <bianpan2016@xxxxxxx>
Reviewed-by: Matthias Brugger <matthias.bgg@xxxxxxxxx>
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/host/xhci-mtk.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/usb/host/xhci-mtk.c
+++ b/drivers/usb/host/xhci-mtk.c
@@ -560,8 +560,10 @@ static int xhci_mtk_probe(struct platfor
 		goto disable_ldos;
 
 	irq = platform_get_irq(pdev, 0);
-	if (irq < 0)
+	if (irq < 0) {
+		ret = irq;
 		goto disable_clk;
+	}
 
 	/* Initialize dma_mask and coherent_dma_mask to 32-bits */
 	ret = dma_set_coherent_mask(dev, DMA_BIT_MASK(32));