Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 20 Jul 1999 23:44:11 +0200 (CEST)
From:      Soren Schmidt <sos@freebsd.dk>
To:        peter@netman.se (Peter Hakanson)
Cc:        gnats-admin@FreeBSD.ORG, freebsd-bugs@FreeBSD.ORG, peter@gbg.netman.se
Subject:   Re: kern/12450: IBM -DTTA-351010 corrupts data when using DMA 32-bit & multi-block i/o
Message-ID:  <199907202144.XAA47470@freebsd.dk>
In-Reply-To: <Pine.BSO.4.10.9907202241370.21509-100000@spock.hq.gbg.netman.se> from Peter Hakanson at "Jul 20, 1999 10:45:58 pm"

next in thread | previous in thread | raw e-mail | index | archive | help
It seems Peter Hakanson wrote:
> Dear "gnats",
> 
> my problem is solved, it might be interesting for you to know the
> cause :
> 
> The board i use (chaintech 5AGM2) has 2 possible "system frequencys"
> for Cyrix-MII, 66 X 3.5 and 75 X 3
> 
> When using 75mhz the ibm disk cannot use DMA, it will
> corrupt data. Quantum does work however.
> 
> When switching to 66 X 3.5 both IBM and quantum works ok.

Ahh, an overclocked system :)

I'll bet that board uses a 37.5 MHz clock for the PCI bus when at 75MHz 
and then also for the IDE channels, putting the timings out of range...
Well, you asked for trouble then :)

-Søren


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-bugs" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199907202144.XAA47470>