From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
This patch reverts commit 3243ff2a05ec ("net: ethernet: davinci_emac:
Deduplicate bus_find_device() by name matching") and adds a comment
which should stop anyone from reintroducing the same "fix" in the future.
We can't use bus_find_device_by_name() here because the device name is
not guaranteed to be 'davinci_mdio'. On some systems it can be
'davinci_mdio.0' so we need to use strncmp() against the first part of
the string to correctly match it.
Fixes: 3243ff2a05ec ("net: ethernet: davinci_emac: Deduplicate bus_find_device() by name matching")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
---
drivers/net/ethernet/ti/davinci_emac.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/ti/davinci_emac.c b/drivers/net/ethernet/ti/davinci_emac.c
index 06d7c9e4dcda..a1a6445b5a7e 100644
--- a/drivers/net/ethernet/ti/davinci_emac.c
+++ b/drivers/net/ethernet/ti/davinci_emac.c
@@ -1385,6 +1385,11 @@ static int emac_devioctl(struct net_device *ndev, struct ifreq *ifrq, int cmd)
return -EOPNOTSUPP;
}
+static int match_first_device(struct device *dev, void *data)
+{
+ return !strncmp(dev_name(dev), "davinci_mdio", 12);
+}
+
/**
* emac_dev_open - EMAC device open
* @ndev: The DaVinci EMAC network adapter
@@ -1484,8 +1489,14 @@ static int emac_dev_open(struct net_device *ndev)
/* use the first phy on the bus if pdata did not give us a phy id */
if (!phydev && !priv->phy_id) {
- phy = bus_find_device_by_name(&mdio_bus_type, NULL,
- "davinci_mdio");
+ /* NOTE: we can't use bus_find_device_by_name() here because
+ * the device name is not guaranteed to be 'davinci_mdio'. On
+ * some systems it can be 'davinci_mdio.0' so we need to use
+ * strncmp() against the first part of the string to correctly
+ * match it.
+ */
+ phy = bus_find_device(&mdio_bus_type, NULL, NULL,
+ match_first_device);
if (phy) {
priv->phy_id = dev_name(phy);
if (!priv->phy_id || !*priv->phy_id)
--
2.17.1
