ethqos->phy_mode is read by serdes_powerup() and qcom_ethqos_set_sgmii_loopback() to configure the SerDes and its wrapper for the correct interface. It is set once at probe from the DT phy-mode property and never updated. phylink resolves the actual runtime interface and passes it to the mac_finish() callback. On platforms that only ever operate at one speed these two values are always the same, but when the interface changes at runtime - for example switching between SGMII and 2500BASE-X - the stored value becomes stale. The next serdes_powerup() call, on a subsequent link cycle, then reinitializes the SerDes to the wrong mode. Update ethqos->phy_mode from the interface argument in ethqos_mac_finish_serdes() so that it always reflects the last resolved interface. With that, we now update the phy_mode to the runtime-resolved interface, so any subsequent resume with a 1G SGMII link skips the loopback setup and the DMA reset hangs. To remedy this, extend the guard to include PHY_INTERFACE_MODE_SGMII. Signed-off-by: Bartosz Golaszewski --- drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c index 47b70b5e706f221c01f1c0ae3b1acafae6641165..e067ceee016217c49d3b3d572fd9f33e562d1a75 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c @@ -190,7 +190,8 @@ static void qcom_ethqos_set_sgmii_loopback(struct qcom_ethqos *ethqos, bool enable) { if (!ethqos->needs_sgmii_loopback || - ethqos->phy_mode != PHY_INTERFACE_MODE_2500BASEX) + (ethqos->phy_mode != PHY_INTERFACE_MODE_2500BASEX && + ethqos->phy_mode != PHY_INTERFACE_MODE_SGMII)) return; rgmii_updatel(ethqos, @@ -634,6 +635,12 @@ static int ethqos_mac_finish_serdes(struct net_device *ndev, void *priv, qcom_ethqos_set_sgmii_loopback(ethqos, false); + /* The interface mode is only known once phylink has resolved it and + * may change at runtime, so keep it in sync for later + * serdes_powerup()/serdes_powerdown() calls. + */ + ethqos->phy_mode = interface; + if (interface == PHY_INTERFACE_MODE_SGMII || interface == PHY_INTERFACE_MODE_2500BASEX) ret = phy_set_mode_ext(ethqos->serdes_phy, PHY_MODE_ETHERNET, -- 2.47.3