eqos: Properly reinitialize TX and RX ring descriptors

[renatoalencar.73_gmail.com]

Summary

When stopping the interface, descriptors aren't properly reinitialized, which can lead to incorrect states that causes the driver to be stuck printing eqos: watchdog timeout. Only fixable after restarting.

Test Plan

• On a SoC snps,dwmac-4.20a compatible
• Run service netif restart with the cable plugged on.
• Run service netif stop with cable unplugged, plug the cable and then run service netif start.
• Run service netif stop with cable plugged, unplug the cable and run service netif start, then plug back the cable.

All of these can render the interface in this state.

[manu]

Thanks,
LGTM but I haven't looked at the NetBSD version, I think that it would be best to keep it synced.

[renatoalencar.73_gmail.com]

In D44484#1016693, @manu wrote:

Thanks,
LGTM but I haven't looked at the NetBSD version, I think that it would be best to keep it synced.

Well, the NetBSD implementation has a couple of key differences on locking and data structures. I was willing to work on trying to make this more similar to theirs. Particularly on improve locking, better hardware support and debugging facilities.