Re: PROBLEM: tg3 spitting out uninitialized memory

[Jamie webb <j@jwebb.sygneca.com>]

Michael Chan wrote:
> On Thu, 2007-04-12 at 16:50 +0200, Andi Kleen wrote:
>> Jamie webb <j@jwebb.sygneca.com> writes:
>>
>>> Hi there
>>>
>>> I have a Dell PE860 with built-in BCM5721, which is reported as
>>> working fine with the tg3 driver, however I have been getting sporadic
>>> data corruption, mostly evident as SSH MAC errors.
>> FWIW i also saw this (data corruption with tg3) occasionally,
>> but never repeatable or with a packet dump.
>>
> My suggestion is to try turning tx checksum off (ethtool -K eth0 tx off)
> to see if it makes a difference.  I'm not aware of checksum problem on
> 5721, but it is worth trying.  See if the other end is reporting TCP
> checksum errors also.

Well, so far so good. I'll let you know if it happens again, but it 
looks like that's fixed it.

Further testing showed that I also had to disable rx checksumming, 
otherwise I was getting random kernel crashes. Presumably it was not 
only reading data from random memory locations, but also writing in the 
wrong place...

So, do I understand correctly that this is causing the CPU rather than 
the NIC to do the checksumming?

Is this a reasonable permanent solution?

Crashing aside, I'm a little nervous about putting into production a box 
that might for example randomly decide to serve up its SSL private keys 
halfway through an email message...

Cheers

/J