From: Timur Tabi <timur.tabi@gmail.com>
To: Scott Wood <scottwood@freescale.com>
Cc: dan.j.williams@intel.com, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] fsldma: add support to 36-bit physical address
Date: Tue, 21 Sep 2010 16:43:12 -0500 [thread overview]
Message-ID: <AANLkTine--kry0c0n87WOqYyi3AQOb2KnmNRs-MeXcQt@mail.gmail.com> (raw)
In-Reply-To: <20100921163456.7e2c9b32@udp111988uds.am.freescale.net>
On Tue, Sep 21, 2010 at 4:34 PM, Scott Wood <scottwood@freescale.com> wrote:
> This doesn't control allocation (it probably should with
> dma_alloc_coherent, though I don't see it in the code), it controls
> whether swiotlb will create a bounce buffer -- defeating the point of
> using DMA to accelerate a memcpy.
But it would do that only for the 'dev' used in the dma_set_mask()
call. That dev is only used here:
chan->desc_pool = dma_pool_create("fsl_dma_engine_desc_pool",
chan->dev,
sizeof(struct fsl_desc_sw),
__alignof__(struct fsl_desc_sw), 0);
Since we don't DMA the descriptors themselves, I just don't see how
this patch does anything.
--
Timur Tabi
Linux kernel developer at Freescale
next prev parent reply other threads:[~2010-09-21 21:43 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-21 10:57 [PATCH] fsldma: add support to 36-bit physical address Li Yang
2010-09-21 12:55 ` Kumar Gala
2010-09-21 21:24 ` Timur Tabi
2010-09-21 21:34 ` Scott Wood
2010-09-21 21:43 ` Timur Tabi [this message]
2010-09-21 21:49 ` Scott Wood
2010-09-21 22:04 ` Timur Tabi
2010-09-21 22:05 ` Dan Malek
2010-09-21 22:08 ` Timur Tabi
2010-09-21 22:17 ` Scott Wood
2010-09-21 22:34 ` Timur Tabi
2010-09-22 5:41 ` Kumar Gala
2010-09-23 22:11 ` Dan Williams
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