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| author | Oleksij Rempel <o.rempel@pengutronix.de> | 2024-11-25 09:40:50 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-12-02 18:56:41 -0800 |
| commit | ccb989e4d1efe0dd81b28c437443532d80d9ecee (patch) | |
| tree | 797ba0f99a623be36810d826532f424b1701b9e9 /drivers | |
| parent | 51ee075d698bb3e8df8287ac80447a18c723dd5a (diff) | |
| download | lwn-ccb989e4d1efe0dd81b28c437443532d80d9ecee.tar.gz lwn-ccb989e4d1efe0dd81b28c437443532d80d9ecee.zip | |
net: phy: microchip: Reset LAN88xx PHY to ensure clean link state on LAN7800/7850
Fix outdated MII_LPA data in the LAN88xx PHY, which is used in LAN7800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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/phy/microchip.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/net/phy/microchip.c b/drivers/net/phy/microchip.c index d3273bc0da4a..691969a4910f 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)); } /** |