Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 16 Nov 1995 12:04:48 -0700 (MST)
From:      Terry Lambert <terry@lambert.org>
To:        koshy@blr.novell.com
Cc:        hackers@FreeBSD.ORG
Subject:   Re: IDE drives using DMA?
Message-ID:  <199511161904.MAA03474@phaeton.artisoft.com>
In-Reply-To: <30aacced0.2096@novidc.blr.novell.com> from "koshy@blr.novell.com" at Nov 16, 95 11:02:00 am

next in thread | previous in thread | raw e-mail | index | archive | help
> I chanced upon a book about ATA drives and noted there that IDE can
> optionally support DMA transfers in addition to the regular programmed
> IO.
> 
> Does anyone have any experience with this?  Are such configurations
> common?  Any catches or caveats that hinder DMA use with IDE drives?

The most common IDE chip, the RZ1000, will silently corrupt data if
you get *any* interrupt during a DMA transfer.

This was discussed in great, gory detail on comp.sys.intel (Intel
makes the RZ1000).

This affects something like 1/3 to 1/2 of all IDE interfaces currently
out there.


					Terry Lambert
					terry@lambert.org
---
Any opinions in this posting are my own and not those of my present
or previous employers.



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199511161904.MAA03474>