From: Vladimir Oltean Date: Wed, 23 Feb 2022 13:20:56 +0000 (+0200) Subject: net: phy: atheros: avoid error in ar803x_of_init() when PHY has no OF node X-Git-Url: http://git.dujemihanovic.xyz/login.html?a=commitdiff_plain;h=5faf161d07099d25fcb67f203c5576f258a11fbf;p=u-boot.git net: phy: atheros: avoid error in ar803x_of_init() when PHY has no OF node A DM_ETH driver may use phy_connect() towards a PHY address on an MDIO bus which is not specified in the device tree, as evidenced by: pfe_eth_probe -> pfe_phy_configure -> phy_connect When this happens, the PHY will have an invalid OF node. When ar803x_config() runs, it silently fails at ar803x_of_init(), and therefore, fails to run the rest of the initialization. This makes MII_BMCR contain what it had after BMCR_RESET (0x8000) has been written into it by phy_reset(). Since BMCR_RESET is volatile and self-clearing, the MII_BMCR ends up having a value of 0x0. The further configuration of this register, which is supposed to be handled by genphy_config_aneg() lower in ar803x_config(), never gets a chance to run due to this early error from ar803x_of_init(). As a result of having MII_BMCR as 0, the following symptom appears: => setenv ethact pfe_eth0 => setenv ipaddr 10.0.0.1 => ping 10.0.0.2 pfe_eth0 Waiting for PHY auto negotiation to complete......... TIMEOUT ! Could not initialize PHY pfe_eth0 Manually writing 0x1140 into register 0 of the PHY makes the connection work, but it is rather desirable that the port works without any manual intervention. Fixes: fe6293a80959 ("phy: atheros: add device tree bindings and config") Signed-off-by: Vladimir Oltean Reviewed-by: Ramon Fried --- diff --git a/drivers/net/phy/atheros.c b/drivers/net/phy/atheros.c index f922fecd6b..fa1fe08518 100644 --- a/drivers/net/phy/atheros.c +++ b/drivers/net/phy/atheros.c @@ -199,7 +199,7 @@ static int ar803x_of_init(struct phy_device *phydev) node = phy_get_ofnode(phydev); if (!ofnode_valid(node)) - return -EINVAL; + return 0; priv = malloc(sizeof(*priv)); if (!priv)