| Message ID | 20241117102147.1688991-1-o.rempel@pengutronix.de (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net,v1,1/1] net: phy: microchip: Reset LAN88xx PHY to ensure clean link state on LAN7800/7850 | expand |
Hi Oleksij, On Sun, 17 Nov 2024 11:21:47 +0100 Oleksij Rempel <o.rempel@pengutronix.de> wrote: > Fix outdated MII_LPA data in the LAN88xx PHY, which is used in LAN7800 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> This looks like the issue in the Asix AX88772A, but your patch has better error handling :) Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Maxime
On Mon, Nov 18, 2024 at 05:48:49PM +0100, Maxime Chevallier wrote: > Hi Oleksij, > > On Sun, 17 Nov 2024 11:21:47 +0100 > Oleksij Rempel <o.rempel@pengutronix.de> wrote: > > > Fix outdated MII_LPA data in the LAN88xx PHY, which is used in LAN7800 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> > > This looks like the issue in the Asix AX88772A, but your patch has > better error handling :) It was my code in Asix. Need to add proper error handling too. It is not nice if device is detached but kernel is continuing executing things and printing a lot of errors.
diff --git a/drivers/net/phy/microchip.c b/drivers/net/phy/microchip.c index d3273bc0da4a..3c8bc87da70e 100644 --- a/drivers/net/phy/microchip.c +++ b/drivers/net/phy/microchip.c @@ -351,6 +351,21 @@ 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, otherwise MII_LPA will provide outdated information. + * This issue is reproducible only with after parallel detection + * where link partner do not supports 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 +392,11 @@ 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)); } /**
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> --- drivers/net/phy/microchip.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) -- 2.39.5