forked from Openwrt-EcoNet/openwrt
b7fa9d92ae
Multiple users have reported a regression [1] in OpenWRT 24.10 with the
ramips/mt7621 target, which has the MT7530 PHYs: the Ethernet link is
periodically going down for a brief period of time:
mt7530-mdio mdio-bus:1f lan1: Link is Down
br-lan: port 1(lan1) entered disabled state
mt7530-mdio mdio-bus:1f lan1: Link is Up - 1Gbps/Full - flow control rx/tx
The symptoms stop after disabling EEE and it was reported by Mediatek in
2021 that EEE is unstable for the MT7530 PHYs [2]:
> EEE of the 10-year-old MT7530 internal gephy has many IOT problems, so
> it is recommended to disable its EEE.
EEE is enabled by default for these devices in OpenWRT 24.10 whereas in the
previous version (OpenWRT 23.05, Linux 5.15) it was not. It was determined
that in Linux 6.6, the PHY driver tries to disable EEE in
mtk_gephy_config_init() in drivers/net/phy/mediatek-ge.c, but this is later
overridden by a subsequent execution of the genphy_c45_write_eee_adv()
function, which enables every EEE mode supported.
The best way forward for now seems to be to mark EEE as broken directly in
the devicetree, which affects the genphy_c45_write_eee_adv() function.
There are some devices, like GnuBee GB-PC2, that define additional PHYs,
for example ethernet-phy@5 or ethernet-phy@7. As reported by Chester A.
Unal, these are not MT7530 PHYs and they are not affected.
This would need to be cherrypicked for the OpenWRT 24.10 branch.
[1] https://github.com/openwrt/openwrt/issues/17351
[2] https://lore.kernel.org/all/0adde34f936a2dafca40b06b408d82afe0852327.camel@mediatek.com/
Tested-by: Darren Tucker
Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Closes: https://github.com/openwrt/openwrt/issues/17351
Link: https://github.com/openwrt/openwrt/pull/18585
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>