[PATCH 3.16 116/129] net: sh_eth: fix a missing check of of_get_phy_mode

[Ben Hutchings]

3.16.70-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Kangjie Lu <k...@umn.edu>

commit 035a14e71f27eefa50087963b94cbdb3580d08bf upstream.

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 <k...@umn.edu>
Reviewed-by: Sergei Shtylyov <sergei.shtyl...@cogentembedded.com>
Reviewed-by: Geert Uytterhoeven <geert+rene...@glider.be>
Tested-by: Geert Uytterhoeven <geert+rene...@glider.be>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
 drivers/net/ethernet/renesas/sh_eth.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -2712,12 +2712,16 @@ static struct sh_eth_plat_data *sh_eth_p
        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)