From: Jeff Garzik <jgarzik@pobox.com>
To: David Gibson <david@gibson.dropbear.id.au>
Cc: James Bottomley <James.Bottomley@steeleye.com>,
linux-kernel@vger.kernel.org
Subject: Re: [RFC] generic device DMA implementation
Date: Wed, 04 Dec 2002 19:54:56 -0500 [thread overview]
Message-ID: <3DEEA3E0.2000306@pobox.com> (raw)
In-Reply-To: <20021205004744.GB2741@zax.zax>
David Gibson wrote:
> On Wed, Dec 04, 2002 at 11:47:14AM -0600, James Bottomley wrote:
>>The new DMA API allows a driver to advertise its level of consistent memory
>>compliance to dma_alloc_consistent. There are essentially two levels:
>>
>>- I only work with consistent memory, fail if I cannot get it, or
>>- I can work with inconsistent memory, try consistent first but return
>>inconsistent if it's not available.
>
>
> Do you have an example of where the second option is useful? Off hand
> the only places I can think of where you'd use a consistent_alloc()
> rather than map_single() and friends is in cases where the hardware's
> behaviour means you absolutely positively have to have consistent
> memory.
agreed, good catch. Returning inconsistent memory when you asked for
consistent makes not much sense: the programmer either knows what the
hardware wants, or the programmer is silly and should not be using
alloc_consistent anyway.
next prev parent reply other threads:[~2002-12-05 0:47 UTC|newest]
Thread overview: 147+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-12-04 17:47 [RFC] generic device DMA implementation James Bottomley
2002-12-04 18:27 ` Jeff Garzik
2002-12-04 19:36 ` James Bottomley
2002-12-04 21:19 ` Miles Bader
2002-12-04 21:21 ` Miles Bader
2002-12-04 21:42 ` James Bottomley
2002-12-05 5:44 ` Miles Bader
2002-12-04 21:46 ` James Bottomley
2002-12-05 2:31 ` Miles Bader
2002-12-05 3:06 ` James Bottomley
2002-12-05 5:02 ` David Gibson
2002-12-05 11:15 ` Benjamin Herrenschmidt
2002-12-05 11:16 ` William Lee Irwin III
2002-12-05 15:12 ` James Bottomley
2002-12-05 0:47 ` David Gibson
2002-12-05 0:54 ` Jeff Garzik [this message]
2002-12-05 1:44 ` James Bottomley
2002-12-05 2:38 ` David Gibson
2002-12-05 3:13 ` James Bottomley
2002-12-05 5:05 ` David Gibson
2002-12-05 15:03 ` James Bottomley
2002-12-05 23:54 ` David Gibson
2002-12-05 3:17 ` Miles Bader
2002-12-05 6:06 ` David Gibson
2002-12-05 6:43 ` Miles Bader
2002-12-05 23:44 ` David Gibson
2002-12-06 2:23 ` Miles Bader
2002-12-05 3:41 ` Jeff Garzik
2002-12-05 6:04 ` David Gibson
2002-12-05 16:29 ` Jeff Garzik
2002-12-05 23:59 ` David Gibson
2002-12-05 11:08 ` Benjamin Herrenschmidt
2002-12-05 11:35 ` Russell King
2002-12-05 15:24 ` James Bottomley
2002-12-06 0:01 ` David Gibson
-- strict thread matches above, loose matches on Subject: below --
2002-12-18 3:01 [RFT][PATCH] " James Bottomley
2002-12-18 3:13 ` David Mosberger
2002-12-28 18:14 ` Russell King
2002-12-28 18:19 ` James Bottomley
2002-12-07 14:37 [RFC] " Adam J. Richter
2002-12-07 4:12 Adam J. Richter
2002-12-06 22:52 Adam J. Richter
2002-12-06 22:17 Adam J. Richter
2002-12-06 22:26 ` James Bottomley
2002-12-06 22:29 ` David S. Miller
2002-12-06 22:48 ` James Bottomley
2002-12-06 22:49 ` David S. Miller
2002-12-06 22:32 ` Arjan van de Ven
2002-12-06 17:39 Adam J. Richter
2002-12-06 18:07 ` Matthew Wilcox
2002-12-06 17:07 Adam J. Richter
2002-12-06 16:48 James Bottomley
2002-12-06 16:19 Adam J. Richter
2002-12-06 16:40 ` Matthew Wilcox
2002-12-06 18:17 ` David S. Miller
2002-12-06 18:29 ` James Bottomley
2002-12-06 18:31 ` David S. Miller
2002-12-06 18:40 ` James Bottomley
2002-12-06 18:42 ` David S. Miller
2002-12-06 21:04 ` Oliver Xymoron
2002-12-07 10:19 ` David Gibson
2002-12-06 18:36 ` Matthew Wilcox
2002-12-06 18:38 ` David S. Miller
2002-12-06 7:41 Adam J. Richter
2002-12-06 15:50 ` David S. Miller
2002-12-06 7:14 Adam J. Richter
2002-12-06 16:26 ` James Bottomley
2002-12-06 17:48 ` Miles Bader
2002-12-07 9:56 ` David Gibson
2002-12-07 9:45 ` David Gibson
2002-12-07 11:26 ` Russell King
2002-12-08 5:28 ` David Gibson
2002-12-06 6:15 David Brownell
2002-12-06 2:08 Adam J. Richter
2002-12-06 2:53 ` David Gibson
2002-12-06 4:03 ` David S. Miller
2002-12-05 20:27 Adam J. Richter
2002-12-05 17:49 Manfred Spraul
2002-12-06 0:08 ` David Gibson
2002-12-05 12:21 Adam J. Richter
2002-12-05 12:44 ` Russell King
2002-12-05 12:13 Adam J. Richter
2002-12-05 11:57 Adam J. Richter
2002-12-06 0:06 ` David Gibson
2002-12-05 5:20 Adam J. Richter
2002-12-05 3:02 Adam J. Richter
2002-12-05 6:15 ` David Gibson
2002-12-05 1:21 Adam J. Richter
2002-12-05 2:40 ` David Gibson
2002-12-05 2:49 ` Miles Bader
2002-12-05 6:12 ` David Gibson
2002-12-05 0:43 Adam J. Richter
2002-12-05 0:55 ` Jeff Garzik
2002-12-05 2:02 ` James Bottomley
2002-11-09 4:51 [parisc-linux] Untested port of parisc_device to generic device interface Adam J. Richter
2002-11-09 5:21 ` Matthew Wilcox
2002-11-09 6:03 ` Greg KH
2002-11-09 15:33 ` J.E.J. Bottomley
2002-11-09 15:33 ` J.E.J. Bottomley
2002-11-09 15:33 ` J.E.J. Bottomley
2002-11-13 6:13 ` Greg KH
2002-11-13 6:13 ` Greg KH
2002-11-13 7:46 ` Miles Bader
2002-11-13 7:46 ` Miles Bader
2002-11-13 7:52 ` Greg KH
2002-11-13 8:02 ` Miles Bader
2002-11-13 8:02 ` Miles Bader
2002-11-13 8:10 ` Greg KH
2002-11-13 8:26 ` Miles Bader
2002-11-13 8:25 ` Greg KH
2002-11-13 9:05 ` Miles Bader
2002-11-13 9:05 ` Miles Bader
2002-11-13 8:25 ` Greg KH
2002-11-13 8:26 ` Miles Bader
2002-11-13 8:10 ` Greg KH
2002-11-13 20:13 ` Grant Grundler
2002-11-13 20:13 ` Grant Grundler
2002-11-13 20:21 ` J.E.J. Bottomley
2002-11-13 20:21 ` J.E.J. Bottomley
2002-11-13 20:37 ` Grant Grundler
2002-11-13 20:37 ` Grant Grundler
2002-11-13 20:21 ` J.E.J. Bottomley
2002-11-13 11:59 ` Ivan Kokshaysky
2002-11-13 12:36 ` Marc Zyngier
2002-11-13 12:36 ` Marc Zyngier
2002-11-13 11:59 ` Ivan Kokshaysky
2002-11-13 16:32 ` Bjorn Helgaas
2002-11-13 16:32 ` Bjorn Helgaas
2002-11-13 17:23 ` J.E.J. Bottomley
2002-11-13 17:23 ` J.E.J. Bottomley
2002-11-13 17:23 ` J.E.J. Bottomley
2002-11-13 20:33 ` Grant Grundler
2002-11-13 20:44 ` J.E.J. Bottomley
2002-11-13 20:44 ` J.E.J. Bottomley
2002-11-13 21:42 ` Grant Grundler
2002-11-13 21:42 ` Grant Grundler
2002-11-13 20:44 ` J.E.J. Bottomley
2002-11-13 20:33 ` Grant Grundler
2002-11-13 20:12 ` Grant Grundler
2002-11-13 20:12 ` Grant Grundler
2002-11-13 7:52 ` Greg KH
2002-11-09 6:03 ` Greg KH
2002-11-09 7:58 ` Marc Zyngier
2002-11-09 7:58 ` Marc Zyngier
2002-11-09 5:21 ` Matthew Wilcox
2002-11-09 18:04 ` Grant Grundler
2002-11-09 18:04 ` Grant Grundler
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=3DEEA3E0.2000306@pobox.com \
--to=jgarzik@pobox.com \
--cc=James.Bottomley@steeleye.com \
--cc=david@gibson.dropbear.id.au \
--cc=linux-kernel@vger.kernel.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.