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<p>Venkatraman S wrote:
<br>> On Wed, Jan 6, 2010 at 6:46 PM, Adrian Hunter <<a href="mailto:adrian.hunter@nokia.com">adrian.hunter@nokia.com</a>>
<br>> wrote:
<br>> > Venkatraman S wrote:
<br>> > >
<br>> > > On Tue, Dec 29, 2009 at 3:18 AM, Tony Lindgren <<a href="mailto:tony@atomide.com">tony@atomide.com</a>>
<br>> wrote:
<br>> > > >
<br>> > > > * Venkatraman S <<a href="mailto:svenkatr@ti.com">svenkatr@ti.com</a>> [091211 07:01]:
<br>> > > > >
<br>> > > > > Here is the most updated version of the patch (thanks to Russell's
<br>> > > > > review). This patch is applicable to OMAP4xxx as well as OMAP3630
<br>> > > > > Reference to previous posts
<br>> > > > > v1 <a href="http://marc.info/?l=linux-omap&m=125012097403050&w=2">http://marc.info/?l=linux-omap&m=125012097403050&w=2</a>
<br>> > > > > v2 <a href="http://marc.info/?l=linux-omap&m=125137152606644&w=2">http://marc.info/?l=linux-omap&m=125137152606644&w=2</a>
<br>> > > > > v3 <a href="http://patchwork.kernel.org/patch/45408/">http://patchwork.kernel.org/patch/45408/</a>
<br>> > > >
<br>> > > > Do you have a patch for drivers/mmc/host/omap_hsmmc.c to
<br>> > > > use this feature? Or some other driver?
<br>> > > >
<br>> > > > Regards,
<br>> > > >
<br>> > > > Tony
<br>> > >
<br>> > > I am about to start working on omap_hsmmc to use the descriptor load
<br>> > > feature. If the DMA changes are acceptable, I can post the driver
<br>> > > patch as well.
<br>> >
<br>> > I presume this is about performance. How does it compare to chained
<br>> DMA?
<br>> > We have a patch for omap_hsmmc for chained DMA that we are still
<br>> testing.
<br>> >
<br>> The main difference would be the number of logical channels used.
<br>> With chaining, I assume you'd request for (or the API internally
<br>> reserves) as many logical channels as there are segments. Here a
<br>> single logical channel would do.
<br>>
<br>
<br>How does the performance compare? Which is faster? Does descriptor autoloading reduce the number of interrupts? </p>
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