6.12-stable review patch. If anyone has any objections, please let me know.
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From: Oleksij Rempel o.rempel@pengutronix.de
[ Upstream commit ccb989e4d1efe0dd81b28c437443532d80d9ecee ]
Fix outdated MII_LPA data in the LAN88xx PHY, which is used in LAN7800 and LAN7850 USB Ethernet controllers. Due to a hardware limitation, the PHY cannot reliably update link status after parallel detection when the link partner does not support auto-negotiation. To mitigate this, add a PHY reset in `lan88xx_link_change_notify()` when `phydev->state` is `PHY_NOLINK`, ensuring the PHY starts in a clean state and reports accurate fixed link parallel detection results.
Fixes: 792aec47d59d9 ("add microchip LAN88xx phy driver") Signed-off-by: Oleksij Rempel o.rempel@pengutronix.de Link: https://patch.msgid.link/20241125084050.414352-1-o.rempel@pengutronix.de Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/phy/microchip.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)
diff --git a/drivers/net/phy/microchip.c b/drivers/net/phy/microchip.c index d3273bc0da4a1..691969a4910f2 100644 --- a/drivers/net/phy/microchip.c +++ b/drivers/net/phy/microchip.c @@ -351,6 +351,22 @@ static int lan88xx_config_aneg(struct phy_device *phydev) static void lan88xx_link_change_notify(struct phy_device *phydev) { int temp; + int ret; + + /* Reset PHY to ensure MII_LPA provides up-to-date information. This + * issue is reproducible only after parallel detection, as described + * in IEEE 802.3-2022, Section 28.2.3.1 ("Parallel detection function"), + * where the link partner does not support auto-negotiation. + */ + if (phydev->state == PHY_NOLINK) { + ret = phy_init_hw(phydev); + if (ret < 0) + goto link_change_notify_failed; + + ret = _phy_start_aneg(phydev); + if (ret < 0) + goto link_change_notify_failed; + }
/* At forced 100 F/H mode, chip may fail to set mode correctly * when cable is switched between long(~50+m) and short one. @@ -377,6 +393,11 @@ static void lan88xx_link_change_notify(struct phy_device *phydev) temp |= LAN88XX_INT_MASK_MDINTPIN_EN_; phy_write(phydev, LAN88XX_INT_MASK, temp); } + + return; + +link_change_notify_failed: + phydev_err(phydev, "Link change process failed %pe\n", ERR_PTR(ret)); }
/**