[PATCH 4.9 05/20] net: phy: xgmiitorgmii: Support generic PHY status read

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

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

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

From: Paul Kocialkowski <paul.kocialkowski@bootlin.com>

[ Upstream commit 197f9ab7f08ce4b9ece662f747c3991b2f0fbb57 ]

Some PHY drivers like the generic one do not provide a read_status
callback on their own but rely on genphy_read_status being called
directly.

With the current code, this results in a NULL function pointer call.
Call genphy_read_status instead when there is no specific callback.

Fixes: f411a6160bd4 ("net: phy: Add gmiitorgmii converter support")
Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/phy/xilinx_gmii2rgmii.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/net/phy/xilinx_gmii2rgmii.c
+++ b/drivers/net/phy/xilinx_gmii2rgmii.c
@@ -42,7 +42,10 @@ static int xgmiitorgmii_read_status(stru
 	u16 val = 0;
 	int err;
 
-	err = priv->phy_drv->read_status(phydev);
+	if (priv->phy_drv->read_status)
+		err = priv->phy_drv->read_status(phydev);
+	else
+		err = genphy_read_status(phydev);
 	if (err < 0)
 		return err;