Intel 82550 Pro/100 Ethernet and Microcode

[Jack Vogel]

I do not own, nor have ever touched the fxp driver, so don't really have an
opinion.

Jack


On Fri, Mar 9, 2012 at 1:36 AM, Adrian Chadd <adrian at freebsd.org> wrote:

> Hi!
>
> That's actually a really good catch!
>
> yongari/jfv, what do you think?
>
>
> Adrian
>
> On 8 March 2012 16:01, Andreas Longwitz <longwitz at incore.de> wrote:
> > Hi,
> >
> > recently I installed FreeBSD 8.2 Stable on some older machines with
> > Intel 82550 and 82550C and found that the loading of microcode with the
> > parameter link0 in the ifconfig command did not work anymore. The reason
> > for this is the commit r223608 for if_fxp.c with the comment:
> >
> > Disable microcode loading for 82550 and 82550C controllers. Loading
> > the microcode caused SCB timeouts.
> >
> > I do not agree with this motivation and try to explain why.
> >
> > Without loading the microcode on 82550(C) there is a problem with
> >   mount_nfs -U server:/bigdisk /mnt
> >   cp /mnt/bigfile bigfile
> >
> > NFS with UDP works with 8 KB blocks and the cp hangs after some seconds
> > and you see SCB messages on the console. The reason is the TCO bug of
> > the hardware mentioned in rcvbundl.h. This old hardware bug disappears
> > after loading the microcode.
> >
> > All my hardware run without problems in FreeBSD 4.11, loading of
> > microcode is done by the function fxp_load_ucode(). Later there was
> > trouble with the loading of microcode, see kern/103332 and kern/118909.
> > I have posted my solution for the problem to kern/103332 but
> > unfortunately this PR is not online anymore and so I repeat my
> > considerations here.
> >
> > The difference of the function fxp_load_ucode() of FreeBSD 4.11 and
> > later versions is that this function in 4.11 has an own private memory
> > buffer for construction of the microcode message. In later versions
> > fxp_load_ucode() must use a memory buffer that is shared with other
> > parts of the driver and these other parts of the driver have problems if
> > the shared memory buffer was used by fxp_load_ucode() before. Thats the
> > reason for "Loading microcode caused SCB timeouts".
> >
> > Therefore my proposal is to revert r223608 and to clean the used shared
> > buffer at the end of the function fxp_load_ucode(). The following patch
> > works for me for years now:
> >
> > --- if_fxp.c.orig       2012-01-26 12:43:09.000000000 +0100
> > +++ if_fxp.c    2012-03-08 23:41:32.000000000 +0100
> > @@ -3085,6 +3081,7 @@
> >            sc->tunable_int_delay,
> >            uc->bundle_max_offset == 0 ? 0 : sc->tunable_bundle_max);
> >        sc->flags |= FXP_FLAG_UCODE;
> > +       bzero(cbp, (uc->length + 2) * sizeof(uint32_t));
> >  }
> >
> >
> > --
> > Dr. Andreas Longwitz
> >
> > Data Service GmbH
> > Beethovenstr. 2A
> > 23617 Stockelsdorf
> > Amtsgericht Lübeck, HRB 318 BS
> > Geschäftsführer: Wilfried Paepcke, Dr. Andreas Longwitz, Josef Flatau
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