Subject: Re: kern/11293: UDMA is unstable on Iwill VD133PL (Apollo MVP3, IDE rev 0x10)
To: Todd P. Whitesel <>
From: Manuel Bouyer <>
List: netbsd-bugs
Date: 10/25/2000 22:02:56
On Wed, Oct 25, 2000 at 01:39:53AM -0700, Todd P. Whitesel wrote:
> The BIOS doesn't let me set that, it only has "Auto" vs. "Disable" for
> both PIO and UDMA, for each of four IDE devices.
> But with a UDMA33 drive, I get the same spurious error behavior.
> --- NOTE ---
> After two days of success, the PIO-only mode tests have now exhibited the
> same spurious errors, with both FreeBSD 4.1.1 and NetBSD 1.5_ALPHA2.
> So that would suggest that this isn't a strictly UDMA issue after all,
> but rather a very subtle VIA PC133 issue... yuck.

Ok. I suspect something like this, because
1) UDMA has crc checks, to errors on the IDE bus should be detected
2) the VIA code is otherwise well tested :)

Manuel Bouyer, LIP6, Universite Paris VI.