From: Matt Porter <mporter@kernel.crashing.org>
To: Bret Indrelee <Bret.Indrelee@qlogic.com>
Cc: Eugene Surovegin <ebs@ebshome.net>,
Linux PPC Embedded mailing list
<linuxppc-embedded@lists.linuxppc.org>
Subject: Re: Any restrictions on DMA address boundry?
Date: Thu, 25 Sep 2003 13:57:46 -0700 [thread overview]
Message-ID: <20030925135746.C17028@home.com> (raw)
In-Reply-To: <Pine.LNX.4.44.0309251526470.12966-100000@spider.ancor.com>; from Bret.Indrelee@qlogic.com on Thu, Sep 25, 2003 at 03:32:13PM -0500
On Thu, Sep 25, 2003 at 03:32:13PM -0500, Bret Indrelee wrote:
>
> On Thu, 25 Sep 2003, Eugene Surovegin wrote:
> > At 12:56 PM 9/25/2003, Matt Porter wrote:
> > >When a buffer is allocated using the allowed methods (as defined in
> > >DMA-mapping.txt) to obtain memory for use in DMA, there is
> > >no guarantee that the buffer is cacheline aligned.
> >
> > Hmm, I don't think this is true.
> >
> > DMA-mapping.txt explicitly states that pci_alloc_consistent() returns
> > aligned memory buffer:
>
> It has been cut from the conversation, but I'm using streaming DMA
> mappings. Specifically, pci_map_single() and pci_unmap_single().
>
> My reading of the 2.4 DMA-mapping.txt is that use of pci_alloc_consistent()
> is specific to Consistent DMA mappings. Same for the pci_pool_ interface.
This is correct. All of my explanation applied to streaming DMA
mappings.
-Matt
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
next prev parent reply other threads:[~2003-09-25 20:57 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-09-22 15:13 Any restrictions on DMA address boundry? Bret Indrelee
2003-09-22 16:59 ` Matt Porter
2003-09-25 17:56 ` Roland Dreier
2003-09-25 18:15 ` Bret Indrelee
2003-09-25 18:26 ` Roland Dreier
2003-09-25 20:54 ` Eugene Surovegin
2003-09-25 19:56 ` Matt Porter
2003-09-25 20:20 ` Bret Indrelee
2003-09-25 20:55 ` Matt Porter
2003-09-25 21:27 ` Bret Indrelee
2003-09-25 20:25 ` Eugene Surovegin
2003-09-25 20:32 ` Bret Indrelee
2003-09-25 20:57 ` Matt Porter [this message]
2003-09-25 20:41 ` Matt Porter
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