P2040: strange behavior of network interface under linux

andy_m — Tue, 10 Apr 2018 15:50:01 GMT

Hi,

our custom P2040 board has five 1G Marvell PHYs (1x88E1510 + 1x88E1340 Quad phy ) connected to the same MDIO bus at addresses 0, 4, 5, 6, 7 , respectively.

U-boot 2016.01 and linux kernel 4.1 based on QorIQ SDK 2.0 are used.

All above network interfaces work as expected in u-boot. Under linux, we observe a weird behavior of one of the network interfaces connected to a quad PHY.

Under llinux, the eth2 (PHY address 5) always shows the link connected and "doesn't auto-negotiate", i.e. the only

way to make it work under linux is to manually turn its auto-negotiation off + set proper speed and duplex mode using

the standard ethtool command. At the same time, the "peer" connected to this interface auto-negotiates correctly regardless of that.

The above suggests that most(or all) related data structures are OK, and this is not a device tree problem.

The only discrepancy observed so far is that the standard PHY identification registers #2 and #3 are always read as zeros for this interface/phyad:5. All other registers read (and written ?) OK.

root:/mnt/ctrl# ./phytool read eth1/4/2
0x0141
root:/mnt/ctrl# ./phytool read eth1/4/3
0x0dc0

root:/mnt/ctrl# ./phytool read eth2/5/2
0000
root:/mnt/ctrl# ./phytool read eth2/5/3
0000

Does this situation look familiar to anyone? What debugging technique should be used in our case?

Thanks.

Re: P2040: strange behavior of network interface under linux

ufedor — Sun, 15 Apr 2018 06:05:42 GMT

Please check that the PHYs are correctly defined in the DTS being used.

P-SeriesのトピックRe: P2040: strange behavior of network interface under linux

P2040: strange behavior of network interface under linux

Re: P2040: strange behavior of network interface under linux