[PATCH 3.16.y-ckt 081/133] stmmac: fix check for phydev being open

[Luis Henriques]

3.16.7-ckt18 -stable review patch.  If anyone has any objections, please let me know.

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

From: Alexey Brodkin <Alexey.Brodkin at synopsys.com>

commit dfc50fcaad574e5c8c85cbc83eca1426b2413fa4 upstream.

Current check of phydev with IS_ERR(phydev) may make not much sense
because of_phy_connect() returns NULL on failure instead of error value.

Still for checking result of phy_connect() IS_ERR() makes perfect sense.

So let's use combined check IS_ERR_OR_NULL() that covers both cases.

Cc: Sergei Shtylyov <sergei.shtylyov at cogentembedded.com>
Cc: Giuseppe Cavallaro <peppe.cavallaro at st.com>
Cc: linux-kernel at vger.kernel.org
Cc: David Miller <davem at davemloft.net>
Signed-off-by: Alexey Brodkin <abrodkin at synopsys.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 641086fc14b5..936cdee0c22e 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -810,8 +810,11 @@ static int stmmac_init_phy(struct net_device *dev)
 
 	phydev = phy_connect(dev, phy_id_fmt, &stmmac_adjust_link, interface);
 
-	if (IS_ERR(phydev)) {
+	if (IS_ERR_OR_NULL(phydev)) {
 		pr_err("%s: Could not attach to PHY\n", dev->name);
+		if (!phydev)
+			return -ENODEV;
+
 		return PTR_ERR(phydev);
 	}