I have this issue with the FEC in 52259, where, after I have set it up (using example code from freertos/lwip), it does cannot receive anything.
I get the rx frame interrupts, which is what I have set-up, but if I look in the descriptor, RX_BD_E is still set, the length is left unchanged from my default.
I have checked all (4 in my case) rx descriptors, but all are as initiated from start. MCF_FEC_ERDSR is, if I read from it, set to the same address as the first descriptor.
All aligned using the run-time alignment method seen in most examples, to 16 bytes.
This is not my first project using the FEC (used it in the 5280 before), still I am lost. I have double checked everything, and really, the example should work out of the box more or less.
So, is there anything obvious I have missed? Is there any condition that can make the FEC give the RX_FRAME interrupt, but leaving the rx descriptors untouched?
As far as I can understand, 52259 does not support data cache, so I think it is not a cache issue.
I have tried to connect it to a 10mbit hub as well as the gigabit switch we use here, with the same outcome. If I unplug the ethernet cable, the interrupts stop coming, so nothing strange with that part.