From: James Bottomley <James.Bottomley@steeleye.com>
To: Ian Molton <spyro@f2s.com>
Cc: david-b@pacbell.net, Linux Kernel <linux-kernel@vger.kernel.org>,
greg@kroah.com, tony@atomide.com, jamey.hicks@hp.com,
joshua@joshuawise.com
Subject: Re: DMA API issues
Date: 18 Jun 2004 19:04:11 -0500 [thread overview]
Message-ID: <1087603453.2135.224.camel@mulgrave> (raw)
In-Reply-To: <20040619005106.15b8c393.spyro@f2s.com>
On Fri, 2004-06-18 at 18:51, Ian Molton wrote:
> Im aware of that but the OHCI core doesnt do that, it uses the DMA API,
> which is entirely reasonable, given its tring to access a DMA-able chunk
> of memory.
>
> I *could* write a new driver ohci-ioremapped for all these chips but its
> needless duplication which is going to result in bugs bveing fixed in
> one ohci driver and not the other.
>
> why not simply expand the DMA API to allow DMA to these easily DMA-able
> chips ?
Because the piece of memory you wish to access is bus remote. Our
current API for bus remote memory requires the use of ioremap and the
accessor functions. Just because it could be accessed directly on ARM
doesn't mean it can be on all platforms. The DMA API is a platform
generic API. To propose an addition to it to make use of this memory,
it would have to work on *all* platforms.
James
next prev parent reply other threads:[~2004-06-19 0:08 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-06-18 18:20 DMA API issues James Bottomley
2004-06-18 18:35 ` Ian Molton
2004-06-18 18:52 ` James Bottomley
2004-06-18 18:57 ` Ian Molton
2004-06-18 19:20 ` David Brownell
2004-06-18 19:44 ` Ian Molton
2004-06-18 19:57 ` James Bottomley
2004-06-18 21:08 ` David Brownell
2004-06-18 21:14 ` James Bottomley
2004-06-18 22:38 ` David Brownell
2004-06-18 23:07 ` James Bottomley
2004-06-18 23:31 ` Ian Molton
2004-06-19 18:23 ` David Brownell
2004-06-19 20:41 ` Russell King
2004-06-19 21:46 ` James Bottomley
2004-06-19 22:49 ` Ian Molton
2004-06-20 13:37 ` James Bottomley
2004-06-20 15:50 ` Ian Molton
2004-06-20 16:26 ` Jeff Garzik
2004-06-20 16:57 ` Ian Molton
2004-06-20 20:15 ` David Brownell
2004-06-20 16:46 ` James Bottomley
2004-06-20 18:02 ` Oliver Neukum
2004-06-20 19:27 ` James Bottomley
2004-06-20 19:34 ` Oliver Neukum
2004-06-20 20:07 ` David Brownell
2004-06-20 20:18 ` David Brownell
2004-06-20 20:02 ` David Brownell
2004-06-18 23:25 ` Ian Molton
2004-06-18 23:29 ` James Bottomley
2004-06-18 23:51 ` Ian Molton
2004-06-19 0:04 ` James Bottomley [this message]
2004-06-19 0:14 ` Ian Molton
2004-06-19 3:49 ` James Bottomley
2004-06-20 20:59 ` Jamey Hicks
2004-06-19 15:11 ` DMA API issues... summary Ian Molton
2004-06-20 20:49 ` Joshua Wise
2004-06-18 19:30 ` DMA API issues James Bottomley
2004-06-18 19:56 ` Ian Molton
2004-06-18 19:22 ` Jamey Hicks
2004-06-18 19:41 ` James Bottomley
2004-06-18 20:02 ` Oliver Neukum
2004-06-18 20:07 ` James Bottomley
2004-06-18 20:14 ` Benjamin Herrenschmidt
2004-06-18 20:24 ` James Bottomley
2004-06-18 21:20 ` Russell King
2004-06-18 23:20 ` Ian Molton
2004-06-20 18:25 ` Deepak Saxena
-- strict thread matches above, loose matches on Subject: below --
2004-06-18 16:59 Ian Molton
2004-06-18 18:07 ` Matt Porter
2004-06-18 18:19 ` Ian Molton
2004-06-18 18:58 ` Matt Porter
2004-06-18 18:33 ` Jamey Hicks
2004-06-18 19:21 ` Matt Porter
2004-06-18 19:43 ` Russell King
2004-06-21 13:35 ` Takashi Iwai
2004-06-21 23:08 ` Russell King
2004-06-22 2:06 ` Jeff Garzik
2004-06-22 3:18 ` Linus Torvalds
2004-06-22 3:26 ` Linus Torvalds
2004-06-22 10:40 ` Takashi Iwai
2004-06-23 12:34 ` Russell King
2004-06-23 15:36 ` Takashi Iwai
2004-06-23 15:44 ` Russell King
2004-06-23 16:01 ` Takashi Iwai
2004-06-23 16:10 ` Russell King
2004-06-22 10:48 ` Takashi Iwai
2004-06-18 19:48 ` Jamey Hicks
2004-06-18 21:08 ` Jeff Garzik
2004-06-18 22:12 ` Richard B. Johnson
2004-06-18 23:27 ` Ian Molton
2004-06-18 23:26 ` Ian Molton
2004-06-18 23:30 ` James Bottomley
2004-06-18 23:32 ` Jeff Garzik
[not found] ` <20040619005714.37b68453.spyro@f2s.com>
[not found] ` <40D3838B.2070608@pobox.com>
[not found] ` <20040619011621.4491600a.spyro@f2s.com>
[not found] ` <40D3872F.5010007@pobox.com>
2004-06-19 0:34 ` Ian Molton
2004-06-19 21:15 ` Tony Lindgren
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=1087603453.2135.224.camel@mulgrave \
--to=james.bottomley@steeleye.com \
--cc=david-b@pacbell.net \
--cc=greg@kroah.com \
--cc=jamey.hicks@hp.com \
--cc=joshua@joshuawise.com \
--cc=linux-kernel@vger.kernel.org \
--cc=spyro@f2s.com \
--cc=tony@atomide.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox