net: ethernet: ezchip: fix error handling

[ Upstream commit 0de449d599594f5472e00267d651615c7f2c6c1d ]

As documented at drivers/base/platform.c for platform_get_irq:

 * Gets an IRQ for a platform device and prints an error message if finding the
 * IRQ fails. Device drivers should check the return value for errors so as to
 * not pass a negative integer value to the request_irq() APIs.

So, the driver should check that platform_get_irq() return value
is _negative_, not that it's equal to zero, because -ENXIO (return
value from request_irq() if irq was not found) will
pass this check and it leads to passing negative irq to request_irq()

Fixes: 0dd077093636 ("NET: Add ezchip ethernet driver")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/ezchip/nps_enet.c b/drivers/net/ethernet/ezchip/nps_enet.c
index 026a3ec..3d74401 100644 (file)
--- a/drivers/net/ethernet/ezchip/nps_enet.c
+++ b/drivers/net/ethernet/ezchip/nps_enet.c
@@ -610,7 +610,7 @@ static s32 nps_enet_probe(struct platform_device *pdev)
 
        /* Get IRQ number */
        priv->irq = platform_get_irq(pdev, 0);
-       if (!priv->irq) {
+       if (priv->irq < 0) {
                dev_err(dev, "failed to retrieve <irq Rx-Tx> value from device tree\n");
                err = -ENODEV;
                goto out_netdev;