tulip driver broken in v5.0.0-rc4

In a qemu-system-hppa system, qemu release v5.0.0-rc, the tulip nic driver is broken.
The tulip nic is detected, even getting DHCP info does work.
But when trying to download bigger files via network, the tulip driver gets stuck.

For example when trying to download a 100MB file:

root@debian:~# wget https://speed.hetzner.de/100MB.bin
--2020-04-23 20:26:43--  https://speed.hetzner.de/100MB.bin
Resolving speed.hetzner.de (speed.hetzner.de)... 88.198.248.254, 2a01:4f8:0:59ed::2
Connecting to speed.hetzner.de (speed.hetzner.de)|88.198.248.254|:443... connected.
<waiting and stuck here>

When reverting this commit, everything works again:
commit 8ffb7265af64ec81748335ec8f20e7ab542c3850
Author: Prasad J Pandit <email address hidden>
Date:   Tue Mar 24 22:57:22 2020 +0530
PATCH: net: tulip: check frame size and r/w data length