On Wed, Feb 23, 2022 at 3:21 PM Vladimir Oltean vladimir.oltean@nxp.com wrote:
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 vladimir.oltean@nxp.com
drivers/net/phy/atheros.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/phy/atheros.c b/drivers/net/phy/atheros.c index f922fecd6b5d..fa1fe08518f4 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)-- 2.25.1
Reviewed-by: Ramon Fried rfried.dev@gmail.com