am3352 cpsw mac freezes after a while

Hi,

We're using 3352 with a micrel 8051PHY on our system. We met a problem that the mac may not sending data after a while.

Initially, the system works fine, we can ping other hosts without problem. The mac may freezes after it's been running for a while. The problem is the buffer descriptor has been put into a tx channel's queue, but its states never change. The owership flag is never cleared by the mac. And the tx_en pin to the PHY is never set to high anymore.

When the problem happened, the mdio still worked fine. Link status changed event can be detected without problem.

And we can recover from the problem by ifdown then ifup the network interface.

The kernel we're using is https://gitorious.org/rowboat/kernel/source/03f2a1e9ea7f8b11ff6809f5a75b614011f8adb6:

Any idea what might be the cause for this problem?

Thanks in advance.