[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Hmm, IDE DMA seems broken with Etch on my PWS433a (Miata MX5).

Lennart Sorensen wrote:
> On Fri, Aug 31, 2007 at 05:02:14PM -0400, Lennart Sorensen wrote:
>> Well there are apparently dip switch settings for 600MHz (after all
>> there was a PWS600a I believe).  The cpu is in a nice ZIF socket, so no
>> problem getting it in and out.  I would have to find the right wrench to
>> move the heat sink over (I love the bolt on heat sink design.  How
>> neat).
>> Not sure about the daughter card bit.  Hmm.  The only other part of the
>> mainboard that seems removable is the 2MB L3 cache module.

Sounds like you could try the CPU swap. But I don't know if the caches
will run at different speeds, though it's be worth the try. If it
doesn't come up, or comes up flakey, you'll know... ;-}

>> Does booting the installer with 'ide=nodma' seem likely to work until I
>> can rebuild the kernel with one of the patches to avoid the DMA bug?
> So the answer to 'ide=nodma' is that for some reason the cmd64x driver
> doesn't even look at any boot options and always enables DMA.  That kind
> of sucks.

I think the latest kernels' cmd64x driver is new - there was a call
recently, on this list IIRC, for help testing the new version, as much
of the IDE support has been totally rewritten, and there are few
instances of the CMD646 (?) in the wild beside built into several of
our Alphas...

> My solutions was to go through the installer to just before the
> partition tool where networking is setup, return to the menu, load
> additional installer features, and install the ssh client.  I then scp'd
> the hdparm binary (from the hdparm udeb I extracted on another machine),
> and ran it to disable dma on the hd.  After that the install when just
> fine.  I then chroot'd to /target, and installed hdparm and configured
> /etc/hdparm.conf to disable dma on the hd on boot.  System boots fine
> with no errors now.

Clever... :-)

> I guess the early miatas require a modified kernel
> to fix the DMA bug in the cmd64x driver.  I am surprised this has never
> made it into the kernel yet.  I guess most people run scsi drives on
> these machines.

Yes, I believe they were never sold with IDE HDDs, just CDs.

If you should decide to try to find a wide SCSI controller, remember
that SRM doesn't know about Adaptec boards. Best bets are QLogic 1040
and NCR 875 and prolly 895. I don't know if there are any supported by
SRM that can do Ultra-3, unfortunately.

Good luck.


Jay A Estabrook                            HPTC - XC I & B
Hewlett-Packard Company - ZKO1-3/D-B.8     (603) 884-0301
110 Spit Brook Road, Nashua NH 03062       Jay.Estabrook@hp.com

Reply to: