public inbox for linuxppc-dev@ozlabs.org 
 help / color / mirror / Atom feed
From: Steven Scholz <steven.scholz@imc-berlin•de>
To: Steve Rossi <srossi@labs•mot.com>
Cc: Embedded Linux PPC List <linuxppc-embedded@lists•linuxppc.org>
Subject: Re: IDE DMA on 8xx ??
Date: Wed, 20 Mar 2002 13:17:47 +0100	[thread overview]
Message-ID: <3C987DEB.14F4E05A@imc-berlin.de> (raw)
In-Reply-To: 3C20E057.B9983C96@labs.mot.com


Hi Steve,

> Has anyone attempted to use the internal 8xx IDMA controller to do
> DMA to a IDE disk? I'm considering making an attempt at it, but I just
> want to hear first if anyone has tried already and if so what the
> experience is.

I did last summer. Well actually I tried. It wasn't too hard to use the
IDMA to transfer data from/to ide disk.

But at that time my code just started polling after setting up the dma.
So the cpu was busy waiting instead of doing something useful. But I
reckon it's not to hard to use irqs for signaling the end of DMA
transfer to the ide driver.

I noticed that the cycle time of the normal (i.e. two-address) IDMA mode
is huge. So the performance wasn't great.

I have to pick up that work again now.

So I wonder if you or anybody else has done something on this topic?

Thanks,

Steven

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

      reply	other threads:[~2002-03-20 12:17 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-12-19 18:45 IDE DMA on 8xx ?? Steve Rossi
2002-03-20 12:17 ` Steven Scholz [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=3C987DEB.14F4E05A@imc-berlin.de \
    --to=steven.scholz@imc-berlin$(echo .)de \
    --cc=linuxppc-embedded@lists$(echo .)linuxppc.org \
    --cc=srossi@labs$(echo .)mot.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox