What's the PIC device? (fwd)

From: Graham Allan <allan_at_mnhep1.hep.umn.edu>
Date: Thu, 06 Aug 1998 21:15:35 -0500

My original question:

One of my Alphastations has crashed recently a couple of times, and the
crash analysis seems to have this as the cause:

_panic_string: 0xfffffc00005d1038 = "pvp: DMA Error by PIC device"

So my question: what *is* the PIC device?

The machine in question is an Alphastation 200 4/233, 128M memory,
ZLXp-L2 graphics, DU 4.0D with patch kit 1. It was also running low on
swap space at the time of crash, though it's not in lazy swap mode, so
it seems unlikely that would be deadly.

------------

I received helpful replies from Dr. Tom Blinn, Whitney Latta (Unix
Expert team), and Alan_at_nabeth.cxo.dec.com (home for wayward inodes, if I
recall correctly :-)

In summary, I should check the Open3D software, then suspect hardware
next.

Part of my question was misleading, as I now realise that patch kit 1
was installed *before* the ZLXp-L2 - so the Open3D patches may well have
not been applied at that time. In any case, there is now a patch kit 2
(though no mention of this graphics card in the release notes), and I
suppose there could be a later revision of the Open3D drivers than those
on the DU4.0D CD - so I have several things to check before swapping the
video card for a spare.

From: alan_at_nabeth.cxo.dec.com

        The message comes from the "pvp" driver, which from the
        other strings appears to be the driver for the graphics
        adapter. Whatever it is, the PIC is probably some component
        that supports DMA transfers, but isn't a happy camper just
        now... You might want to check with MCS to see if it could
        be a software bug with a patch, otherwise look into having
        the graphics adapter fixed/replaced.

From: "Dr. Tom Blinn, 603-884-0646" <tpb_at_zk3.dec.com>

The ZLXp-L2 graphics adapter is also known as the "pvp" as an internal
code name in the graphics software support group. The "PIC" device is
part of the hardware on that graphics card; I don't remember exactly
what the "PIC" acronym is supposed to stand for, but it's something like
"programmable interrupt controller". It's one of the active logic
components on the PCI graphics card.

This sounds like a bug in the Open3D software. I don't claim to know if
the ZLXp-L2 is still officially supported by the current version of
Open3D; you would have to double-check the Open3D release notes and
installation guide, the Open3D group has a history of retiring support
for certain options on a relatively short and inconspicuous notice. If
you verify that the ZLXp-L2 is in fact supposed to be supported by
Open3D.latest, you might reinstall the Open3D software (latest kit) and
rebuild the kernel to see if this will go away. Otherwise, it may be an
incompatibility between the Open3D you've got and the patches.

I doubt that anyone in the Open3D group tests with the patches
installed, and I doubt that the group responsible for testing the patch
kits has all of the various graphics adapters or installs and tests
Open3D, so there is some possibility that an incompatibility could arise
and not get caught before the patch kit shipped.

From: Whitney Latta <latta_at_decatl.alf.dec.com>

The graphics device, ie: ZLXp-L2

The panic you observe is caused by either downrev Open3d drivers (obtain
and load the latest version), or hardware. I would start with the Open3d
software first!

I hope this helps.


-- 
Received on Fri Aug 07 1998 - 02:17:00 NZST

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