From: akepner@sgi.com
To: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Andrew Morton <akpm@linux-foundation.org>,
grundler@parisc-linux.org, jbarnes@virtuousgeek.org, jes@sgi.com,
randy.dunlap@oracle.com, rdreier@cisco.com,
James.Bottomley@steeleye.com, davem@davemloft.net,
linux-kernel@vger.kernel.org
Subject: Re: [RFC] dma: passing "attributes" to dma_map_* routines
Date: Thu, 20 Dec 2007 11:06:42 -0800 [thread overview]
Message-ID: <20071220190642.GM412@sgi.com> (raw)
In-Reply-To: <476834AC.9050401@s5r6.in-berlin.de>
On Tue, Dec 18, 2007 at 09:59:24PM +0100, Stefan Richter wrote:
>
> From its purpose it sounds like you need this only for few special
> memory regions which would typically be mapped by dma_map_single()
We need the _sg versions too, as Roland already mentioned.
> .... and
> furthermore that drivers who need this behavior will be changed to
> explicitly demand it. If so, a nonintrusive API extension could simply
> be to add an
>
> dma_addr_t dma_map_single_write_last(struct device *dev, void *ptr,
> size_t size, enum dma_data_direction direction);
> ...
This is the easiest thing to do, and therefore it'd be my
preference. But I'm concerned that the keepers of the dma
interface will object to this. So far they've been silent
in this thread - maybe they need to see a patch before
they'll get engaged....
--
Arthur
next prev parent reply other threads:[~2007-12-20 19:08 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-18 0:17 [RFC] dma: passing "attributes" to dma_map_* routines akepner
2007-12-18 16:50 ` Stefan Richter
2007-12-18 19:04 ` Roland Dreier
2007-12-18 20:07 ` akepner
2007-12-18 20:59 ` Stefan Richter
2007-12-18 21:09 ` Roland Dreier
2007-12-20 18:51 ` akepner
2007-12-20 19:06 ` akepner [this message]
2007-12-20 20:56 ` Benjamin Herrenschmidt
2007-12-21 18:00 ` akepner
2007-12-21 20:24 ` Stefan Richter
2007-12-21 21:31 ` Benjamin Herrenschmidt
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