From: Emanuele Ghidoli emanuele.ghidoli@toradex.com
[ Upstream commit 84a905290cb4c3d9a71a9e3b2f2e02e031e7512f ]
While the DP83867 PHYs report EEE capability through their feature registers, the actual hardware does not support EEE (see Links). When the connected MAC enables EEE, it causes link instability and communication failures.
The issue is reproducible with a iMX8MP and relevant stmmac ethernet port. Since the introduction of phylink-managed EEE support in the stmmac driver, EEE is now enabled by default, leading to issues on systems using the DP83867 PHY.
Call phy_disable_eee during phy initialization to prevent EEE from being enabled on DP83867 PHYs.
Link: https://e2e.ti.com/support/interface-group/interface/f/interface-forum/14452... Link: https://e2e.ti.com/support/interface-group/interface/f/interface-forum/65863... Fixes: 2a10154abcb7 ("net: phy: dp83867: Add TI dp83867 phy") Cc: stable@vger.kernel.org Signed-off-by: Emanuele Ghidoli emanuele.ghidoli@toradex.com Reviewed-by: Andrew Lunn andrew@lunn.ch Link: https://patch.msgid.link/20251023144857.529566-1-ghidoliemanuele@gmail.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/phy/dp83867.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/net/phy/dp83867.c b/drivers/net/phy/dp83867.c index 4120385c5a79d..e02e3479e1c7a 100644 --- a/drivers/net/phy/dp83867.c +++ b/drivers/net/phy/dp83867.c @@ -792,6 +792,12 @@ static int dp83867_config_init(struct phy_device *phydev) return ret; }
+ /* Although the DP83867 reports EEE capability through the + * MDIO_PCS_EEE_ABLE and MDIO_AN_EEE_ADV registers, the feature + * is not actually implemented in hardware. + */ + phy_disable_eee(phydev); + if (phy_interface_is_rgmii(phydev) || phydev->interface == PHY_INTERFACE_MODE_SGMII) { val = phy_read(phydev, MII_DP83867_PHYCTRL);