[PATCH 4.17 080/324] net: davinci_emac: match the mdio device against its compatible if possible

[Greg Kroah-Hartman]

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

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

From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>

[ Upstream commit ea0820bb771175c7d4192fc6f5b5c56b3c6d5239 ]

Device tree based systems without of_dev_auxdata will have the mdio
device named differently than "davinci_mdio(.0)". In this case use the
device's parent's compatible string for matching

Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/ti/davinci_emac.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/net/ethernet/ti/davinci_emac.c
+++ b/drivers/net/ethernet/ti/davinci_emac.c
@@ -1387,6 +1387,10 @@ static int emac_devioctl(struct net_devi
 
 static int match_first_device(struct device *dev, void *data)
 {
+	if (dev->parent && dev->parent->of_node)
+		return of_device_is_compatible(dev->parent->of_node,
+					       "ti,davinci_mdio");
+
 	return !strncmp(dev_name(dev), "davinci_mdio", 12);
 }