MPC8569 PHY communication issue

[hemwant]

We are having two DP83848 phys connected with MPC8569 processor, the phy are connected on UCC1 and UCC5 respectively. The mode of connection of the PHY is RMII. The PHYs are working propery when configured properly. In one of the rare case in one specific board, after reset of the processor PHY fail to ping the external network. The kernel dump of the same is attached in this thread. 

When we tried to debug the packets using tcpdump, the link started working properly in one of the PHY. In second PHY we have manually read all the UCC5 registers.

Please suggest what can be done in such a scenario to restore the link?

[hemwant]

@bpeI will check the clock status of the UCC when this issue arises again. Thereafter will update this chain thread

[bpe]

There is nothing particularly wrong in the registers you attached. Note that the
link is established by the PHY, not by the MAC. If you are concerned with that,
diagnose the PHY. Your kernel output displays a NETDEV Watchdog timeout message.
It basically means, that the UCC is not handling it's Tx BD rings. One typical
situation where it happens is lack of the interface clock. This is where you
can start your diagnostics: check how your UCC is configured to receive clocks
and make sure the clock is present. More details can be found in QEIWRM,
Section 5.5.

Hope this helps,
Platon