[PATCH AUTOSEL 4.4 058/174] net: sh_eth: fix a missing check of of_get_phy_mode

[Sasha Levin <sashal@kernel.org>]

From: Kangjie Lu <kjlu@umn.edu>

[ Upstream commit 035a14e71f27eefa50087963b94cbdb3580d08bf ]

of_get_phy_mode may fail and return a negative error code;
the fix checks the return value of of_get_phy_mode and
returns NULL of it fails.

Fixes: b356e978e92f ("sh_eth: add device tree support")
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Reviewed-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/renesas/sh_eth.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
index 2d9f4ed9a65e..8413f93f5cd9 100644
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -3040,12 +3040,16 @@ static struct sh_eth_plat_data *sh_eth_parse_dt(struct device *dev)
 	struct device_node *np = dev->of_node;
 	struct sh_eth_plat_data *pdata;
 	const char *mac_addr;
+	int ret;
 
 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
 		return NULL;
 
-	pdata->phy_interface = of_get_phy_mode(np);
+	ret = of_get_phy_mode(np);
+	if (ret < 0)
+		return NULL;
+	pdata->phy_interface = ret;
 
 	mac_addr = of_get_mac_address(np);
 	if (mac_addr)
-- 
2.20.1