busdma MFC broke ipfw fwd for RELENG_6

[YongHyeon PYUN]

On Fri, Sep 16, 2011 at 12:41:23AM +0700, Eugene Grosbein wrote:
> 16.09.2011 00:14, John Baldwin пишет:
> > On Thursday, September 15, 2011 12:44:32 pm Eugene Grosbein wrote:
> >> Hi!
> >>
> >> I understand that it is "a bit" late for RELENG_6 reports as 6.4-RELEASE was out in 2008
> >> but the breakage had happened due to MFC so it's possible same problem exists in newer branches.
> >>
> >> Long story short: I've updated my old 6.4-STABLE system for recent zoneinfo updates
> >> and found the update broke 'ipfw fwd' feature: forwarded packets get corrupted,
> >> routed packets go just fine.
> >>
> >> The commit in question has been performed in 2010/08/06:
> >> http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/i386/i386/Attic/busdma_machdep.c.diff?r1=1.74.2.6;r2=1.74.2.7
> >>
> >> I've rolled it back using recent RELENG_6 sources and packet corruption have disappeared.
> > 
> > It may be a bug in the rl(4) driver?  Perhaps this is a candidate to try?
> > 
> > http://svnweb.freebsd.org/base?view=revision&revision=184240
> > 
> 
> My system is i386 with 512MB RAM only and outgoing packets go through re(4), not rl(4).
> 
> Nevertheless, I've just applied revision 184240 to RELENG_6 manualy (it did not apply cleanly)
> and reapplied MFC. The problem has returned.
> 

I remember re(4) in 6.x also have a couple of bus_dma(9) bugs. How
about applying the following revision?
http://svnweb.freebsd.org/base?view=revision&revision=175337
Not sure whether it shall apply cleanly.
Alternatively try replacing BUS_DMA_ALLOCNOW to 0 in
bus_dma_tag_create(9).

> Eugene Grosbein