[PATCH net 0/3] net: phy: realtek: fix status when link is down

From: Daniel Golle
Date: Wed Jan 15 2025 - 09:44:36 EST


The .read_status method for RealTek RTL822x PHYs (both C22 and C45) has
multilpe issues which result in reporting bogus link partner advertised
modes as well as speed and duplex while the link is down and no cable
is plugged in.

Example: ethtool after disconnecting a 1000M/Full capable link partner,
now with no wire plugged:

Settings for lan1:
Supported ports: [ TP ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
2500baseT/Full
Supported pause frame use: Symmetric Receive-only
Supports auto-negotiation: Yes
Supported FEC modes: Not reported
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
2500baseT/Full
Advertised pause frame use: Symmetric Receive-only
Advertised auto-negotiation: Yes
Advertised FEC modes: Not reported
Link partner advertised link modes: 1000baseT/Full
Link partner advertised pause frame use: No
Link partner advertised auto-negotiation: No
Link partner advertised FEC modes: Not reported
Speed: 1000Mb/s
Duplex: Full
Auto-negotiation: on
Port: Twisted Pair
PHYAD: 7
Transceiver: external
MDI-X: Unknown
Supports Wake-on: d
Wake-on: d
Link detected: no

Fix this by making sure all of the fields populated by
rtl822x_c45_read_status() or rtl822x_read_status() get reset, also in
case the link is down.

Daniel Golle (3):
net: phy: realtek: clear 1000Base-T lpa bits if link is down
net: phy: realtek: clear master_slave_state if link is down
net: phy: realtek: always clear 10gbase-t link partner advertisement

drivers/net/phy/realtek.c | 29 ++++++++++++++---------------
1 file changed, 14 insertions(+), 15 deletions(-)

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2.47.1