Re: Disabling UDP checksums on HME

[Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>]

> Looking at:
> 
>   http://bugs.opensolaris.org/bugdatabase/view_bug.do?bug_id=6587521
> 
> and related bugs, sun ethernet cards have a UDP checksum bug where a
> checksum of 0x0000 is not converted to 0xffff.
> 
> So, it looks like we should disable UDP checksums for hme(4)

I guess disabling only udp4csum-tx is enough.

> and also
> calculate software checksums when the packet length is less than 64
> bytes.

I think you are talking about bug #6587521
http://bugs.opensolaris.org/bugdatabase/view_bug.do?bug_id=6587116
but it doesn't mention how badly the hardware calculates sums.

I wonder if manual padding can help it or not, but
I can't reproduce UDP packets with wrong cksum
on quick tests with PCI hme(4).
---
Izumi Tsutsui