100G E-Tile transceiver adaptation

Minor update to this, just to rule out some possible settings combinations:

• "Adaptation load soft IP" off, xcvr_reconfig tied off (no reconfig logic): no link, need to adjust adaptation settings in system console to get an RX link
• "Adaptation load soft IP" on and NRZ_28Gbps_LR selected and settings saved in config 0, xcvr_reconfig tied off (no reconfig logic): no link, need to adjust adaptation settings in system console to get an RX link
• "Adaptation load soft IP" on and NRZ_28Gbps_LR selected and settings saved in config 0, xcvr_reconfig connected to state machine: no link, need to adjust adaptation settings in system console to get an RX link (and state machine is stuck trying to trigger the PMA configuration streamer, which never appears to start)

Hardware config:

FPGA (DE10-Agilex rev B with AGFB014R24A2E2VR0) E-Tile -> QSFP-DD cage -> QSFP28 DAC -> Mellanox ConnectX-5 NIC

In this case, the ConnectX-5 reports that the link is up at 100 Gbps, but rx_pma_ready on the E-Tile is low. If take the settings that the transceivers get when in 25G mode and apply them via the system console, then the link does come up. Question is how to do that without involving the system console.

Edit: and I just tested with a 30M AOC, and I was able to get a link. So, apparently the default parameters on the E-Tile transceivers will work with AOCs with integrated CDRs, but not DACs. However, the same exact DAC works perfectly with Xilinx UltraScale+ devices at 100G, and with the E-Tile at 25G (with the adaptation load soft IP working to configure the transceivers), so it seems like the E-Tile should be able to work in this situation.