From: Bartosz Golaszewski bgolaszewski@baylibre.com
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@vger.kernel.org Signed-off-by: Bartosz Golaszewski bgolaszewski@baylibre.com Acked-by: Lukas Wunner lukas@wunner.de --- 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)