Pressing Z failed instantly, BEFORE the sender was started -- so the frames
in the ring were stray traffic from the host (mDNS, IPv6 RAs, ARP), and a
single descriptor we could not parse aborted the whole transfer. On a live
network that is guaranteed to happen.
A bad descriptor is now non-fatal: log the first few, resync RRP to the
gateware's RWP, and keep waiting. Capped at 200 so a genuinely broken ring
still terminates rather than spinning. This also removes the dependence on
the ring being quiet when Z is pressed, which was never a reasonable
assumption.
The descriptor 00 00 00 01 persists after fixing both dropped-write bugs, and
grep confirms no bare `ready` tests remain, so it is NOT that. Rather than
theorise a fourth time, the error path now dumps 32 bytes from the head of the
offending page. That distinguishes the two remaining possibilities outright:
an ethernet header at offset 4 means the descriptor length is simply wrong,
while a header at 3 or 5 -- or at 0 -- means we are reading the wrong place.
Also dumps the first frame whose ethertype does not match, with the ethertype
read at offset 12, because a body written at the wrong offset would show the
ethertype at 11 or 13. And the timeout now reports how many frames were seen
and how many descriptors were rejected, so "no match" is distinguishable from
"nothing arrived".
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Roflin
0477e07b84