[prev in list] [next in list] [prev in thread] [next in thread]
List: linux-bridge
Subject: Re: [Bridge] sky2 hw csum failure
From: Stephen Hemminger <shemminger () vyatta ! com>
Date: 2011-11-15 17:45:16
Message-ID: 20111115094516.3eb54a1a () nehalam ! linuxnetplumber ! net
[Download RAW message or body]
On Tue, 15 Nov 2011 18:28:55 +0800
"Yan, Zheng" <zheng.z.yan@intel.com> wrote:
> I re-tested the checksum code, both CHECKSUM_NONE and CHECKSUM_COMPLETE
> cases are OK. Maybe the bug is related to sky2.
>
> Regards
> Yan, Zheng
There are three types of receive checksumming:
1. Hardware does not do checksumming (CHECKSUM_NONE)
2. Hardware validates checksum (CHECKSUM_UNNECESSARY)
3. Hardware computes sum of bytes in skb (CHECKSUM_COMPLETE)
Most hardware does #2, but sky2 uses #3.
For the second case, the hardware does not look at headers but only
reports the one's complement value in ip_summed. It is up to the
protocol layers to adjust accordingly. This means if data is removed
or added the checksum needs to be adjusted.
_______________________________________________
Bridge mailing list
Bridge@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/bridge
[prev in list] [next in list] [prev in thread] [next in thread]
Configure |
About |
News |
Add a list |
Sponsored by KoreLogic