cvs commit: src/sys/dev/em if_em.c

Eric Anderson anderson at
Tue Aug 22 15:26:05 UTC 2006

On 08/22/06 10:23, Gleb Smirnoff wrote:
> On Tue, Aug 22, 2006 at 02:32:48AM +0000, Pyun YongHyeon wrote:
> P> yongari     2006-08-22 02:32:48 UTC
> P> 
> P>   FreeBSD src repository
> P> 
> P>   Modified files:
> P>     sys/dev/em           if_em.c 
> P>   Log:
> P>   It seems that em(4) misses Tx completion interrupts under certain
> P>   conditions. The cause of missing Tx completion interrupts comes from
> P>   Tx interrupt moderation mechanism(delayed interrupts) or chipset bug.
> P>   If Tx interrupt moderation mechanism is the cause of false watchdog
> P>   timeout error we should have to fix all device drivers that have Tx
> P>   interrupt moderation capability. We may need more investigation
> P>   for this issue. Anyway, the fix is the same for both cases.
> P>   
> P>   This should fix occasional watchdog timeout errors seen on a few
> P>   systems.
> P>   
> P>   Reported by:    -net, Patrick M. Hausen < hausen AT punkt DOT de >
> P>   Tested by:      Patrick M. Hausen < hausen AT punkt DOT de >
> This look like a workaround, not a fix the root of the problem. Several
> people on net said that this problem disappears if debug.mpsafenet=0.
> So I think there is a problem in FreeBSD or driver, not in chip.

And it also worked perfectly for a very very long time until 6.x tree. 
I went from 5-STABLE to 6-STABLE and started seeing it a lot ( a few 
times per day) on a couple servers.


Eric Anderson        Sr. Systems Administrator        Centaur Technology
Anything that works is better than anything that doesn't.

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