AR# 66553

PetaLinux, Zynq UltraScale+ MPSoC: Ethernet link between ZCU102 and a host machine at 100M/Full does not work

Description

The Ethernet link between my ZCU102 board and a host machine at 100M/Full does not work. The link keeps going up and down:

[  289.532997] macb ff0e0000.ethernet eth0: unable to generate target frequency: 25000000 Hz
[  289.541083] macb ff0e0000.ethernet eth0: link up (100/Full)
[  295.542950] macb ff0e0000.ethernet eth0: link down
[  297.543012] macb ff0e0000.ethernet eth0: unable to generate target frequency: 25000000 Hz
[  297.551100] macb ff0e0000.ethernet eth0: link up (100/Full)
[  299.552951] macb ff0e0000.ethernet eth0: link down

Solution

In PetaLinux 2015.4, 2016.1 and 2016.2, dynamic speed switching is not possible. Only the default speed of 1G is supported.

This is NOT a silicon or board limitation but a Linux infrastructure (to enable dynamic speed switching) being under development and not ready yet.

Work-around:

Configure the host machine to "Auto-negotiation" or "1G/Full".

This is (tentatively) planned to be fixed for the 2016.3 release.

AR# 66553
Date 07/01/2016
Status Active
Type General Article
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