AM5726: AM5726 RGMII loopback

Do you mean GMAC is working if LOOPBACK mode is not enabled?

Ioan Marusca said:

AM5726 customer board works well sending and receiving packets. Only RGMII0 is used.

Yes. The board works well and sends/receives packets in normal mode of operation (no loopback). 

We only support loopback mode for either internal loopback or external loopback from PHY.

I need to have CPU closing the loop-back as per paragraph 24.11.4.18.13 of TRM.

HI

There are two modes in which we can use FIFO loopback - can you clarify the intended use case.

1. Application running on the SoC generates traffic with CPU(with DMA) port configured in loopback mode. Here we expect the CPSW module to loopback the traffic back to the CPU port, hence application will receive back the packets sent
2. The external facing ports are configured in loopback mode and you are trying to bring in traffic from external device

Loopback is typically use only as debug aid - can you clarify the intent

The scenario #2 is the one I'm trying to use.

This is for hardware/software debugging purpose. 

Hello Loan M.,

External loopback mode (PC sends data to MAC port which routes it back to PC again) can be achieved by setting FIFO loopback bit in the CPSWcontrol register (0x4848_4004) of AM57x.