All of lore.kernel.org
 help / color / mirror / Atom feed
From: msokolov@ivan.Harhan.ORG (Michael Sokolov)
To: linuxppc-dev@lists.linuxppc.org
Subject: Re: ISA DMA take 2
Date: Wed, 9 Jan 02 09:53:06 PST	[thread overview]
Message-ID: <0201091753.AA22414@ivan.Harhan.ORG> (raw)


Adrian Cox <adrian@humboldt.co.uk> wrote:

> Yes - and I set ISA_DMA_THRESHOLD to 0x00ffffff. It's not possible to
> use ISA DMA with the Via southbridge unless you have main memory at 0x0
> on the PCI bus.

As I understand it, you also have to have no I/O hole in the mapping of the
bottom 16 MB of memory onto PCI, right? As I understand it, Linux/PPC is a sane
PPC OS and treats all PPC memory as normal, without any special treatment for
0xA0000-0xFFFFF, so your DMA buffer could legitimately end up in that region
and if your memory map has an I/O hole you would be screwed, right? And of
course main memory on PCI at 0 with no I/O hole means you can't have video on
the same PCI bus... !@#$ing pee sea legacy :(

MS

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

             reply	other threads:[~2002-01-09 17:53 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-01-09 17:53 Michael Sokolov [this message]
2002-01-09 18:27 ` ISA DMA take 2 Adrian Cox
  -- strict thread matches above, loose matches on Subject: below --
2002-01-09 20:18 Michael Sokolov
2002-01-09 20:43 ` Adrian Cox
2002-01-09 17:21 Michael Sokolov
2002-01-09 17:40 ` Adrian Cox
2002-01-08 15:33 Adrian Cox

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=0201091753.AA22414@ivan.Harhan.ORG \
    --to=msokolov@ivan.harhan.org \
    --cc=linuxppc-dev@lists.linuxppc.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.