Re: Lenovo X60 em workaround

> Since this was just seen, and the patch below validated as working I wanted
> to send general email to capture this:
> 
> The Lenovo X60 can have issues with long ping times, this is a KNOWN
> hardware problem, and Intel is working with IBM/Lenovo, a final 'fix' has
> not been decided on yet. Nevertheless, the patch below will work, but
> I do not want to check it in as its still temporary.
>
> Address questions to me,

Okay, I have a question. Could you elaborate on just what the problem is?
(I mean, since it's KNOWN and all...) I'm just having a hard time figuring
out what problem could possibly be fixed by setting the RX interrupt
delay timer to a non-zero value (especially since elsewhere in the em(4)
source it says that doing so is a Bad Thing (tm)).

-Bill

> Jack
> 
> PS This is based on 6.2, but is needed for CURRENT as well.
> 
> 
> --- if_em.dist.c        Wed Jan 17 17:59:46 2007
> +++ if_em.c     Wed Jan 17 18:03:13 2007
> _at__at_ -3348,6 +3348,10 _at__at_
>                 E1000_WRITE_REG(&adapter->hw, RXCSUM, reg_rxcsum);
>         }
> 
> +       /* TEMPORARY WORKAROUND for X60 */
> +       if (adapter->hw.mac_type == em_82573)
> +               E1000_WRITE_REG(&adapter->hw, RDTR, 32);
> +
>         /* Enable Receives */
>         E1000_WRITE_REG(&adapter->hw, RCTL, reg_rctl);
>         /*
>