Subject: [BUG] mv88e6xxx: tx regression in v5.3

From: Baruch Siach <[email-masked]>
Date: Wed, 11 Dec 2019 11:48:57 +0200

Hi Andrew, Vivien,

Since kernel v5.3 (tested v5.3.15), the 88E6141 switch on SolidRun
Clearfog GT-8K stopped transmitting packets on switch connected
ports. Kernel v5.2 works fine (tested v5.2.21).

Here are the relevant kernel v5.3 log lines:

[    2.867424] mv88e6085 f412a200.mdio-mii:04: switch 0x3400 detected: Marvell 88E6141, revision 0
[    2.927445] libphy: mdio: probed
[    3.578496] mv88e6085 f412a200.mdio-mii:04 lan2 (uninitialized): PHY [!cp1!config-space@f4000000!mdio@12a200!switch0@4!mdio:11] driver [Marvell 88E6390]
[    3.595674] mv88e6085 f412a200.mdio-mii:04 lan1 (uninitialized): PHY [!cp1!config-space@f4000000!mdio@12a200!switch0@4!mdio:12] driver [Marvell 88E6390]
[    3.612797] mv88e6085 f412a200.mdio-mii:04 lan4 (uninitialized): PHY [!cp1!config-space@f4000000!mdio@12a200!switch0@4!mdio:13] driver [Marvell 88E6390]
[    3.629910] mv88e6085 f412a200.mdio-mii:04 lan3 (uninitialized): PHY [!cp1!config-space@f4000000!mdio@12a200!switch0@4!mdio:14] driver [Marvell 88E6390]
[    3.646049] mv88e6085 f412a200.mdio-mii:04: configuring for phy/ link mode
[    3.654451] DSA: tree 0 setup
...
[   10.784521] mvpp2 f4000000.ethernet eth2: configuring for fixed/2500base-x link mode
[   10.792401] mvpp2 f4000000.ethernet eth2: Link is Up - 2.5Gbps/Full - flow control off
[   19.817981] mv88e6085 f412a200.mdio-mii:04 lan1: configuring for phy/ link mode
[   19.827083] 8021q: adding VLAN 0 to HW filter on device lan1
[   21.577276] mv88e6085 f412a200.mdio-mii:04 lan1: Link is Up - 100Mbps/Full - flow control rx/tx
[   21.586030] IPv6: ADDRCONF(NETDEV_CHANGE): lan1: link becomes ready

The Tx count on the lan1 interface increments, but the ARP packets don't
show on the network.

Do you have any idea?

Thanks,
baruch

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