AIC-7902 problems

[John Kamei]

> FWIW, we have just run into the same issue with new supermicro
> X5 motherboards as well. Downgrading the system bios to c182 from
> 1.3c (no idea what these mean:) made the problem go away.
> We are working with supermicro support on it right now.

As I mentioned to Don in private email, I believe that this problem
is caused by an errata in the P64H2 PCI-X hub.  Information about
this errata can be found here:

http://developer.intel.com/design/chipsets/e7500/specupdt/290735.htm

My suspicion is that the SCBs for some transactions are getting
partially corrupted so the command that we think we are sending
to the drive is not really getting sent.  A good way to verify this
is to force the PCI-X bus into PCI mode.  The problem is supposed
to only occur if there is another device on the PCI-X bus sharing
the 7902, but it would not surprise me if the 7902 could also be
hit with an unexpected GNT.

I will be working with Supermicro to see if I can get both a PCI-X
and SCSI bus trace to help isolate the problem.

--
Justin

Have these problems been resolved? Is the only way to get around this is to
turn off packetization on the BIOS?

Thanks