From: Clemens Koller <clemens.koller@anagramm•de>
To: Dan Malek <dan@embeddededge•com>
Cc: linuxppc-embedded@ozlabs•org
Subject: Re: MPC85xx DMA support for Kernel 2.6?
Date: Fri, 01 Jul 2005 09:47:25 +0200 [thread overview]
Message-ID: <42C4F50D.3050405@anagramm.de> (raw)
In-Reply-To: <427c70958bb995dad4fbad2e6ff121bc@embeddededge.com>
Hi, Dan!
Dan Malek wrote:
> Before you start, just make sure such a thing is really a performance
> enhancement. Yes, the DMA does run in parallel with the core, but often
> the overhead of the set up and clean up interrupt is more code and time
> that if you just copied the data in a loop. If possible, integrate the DMA
> processing into other driver work, clean up a previous DMA the next time
> the driver needs to use it, not with a separate completion handler.
Well... thanks. But the CPU is intended to do image processing while
data comes in. And currently, when I access (memcopy) the SRAM on my
Local Bus via UPM I cannot get it to generate bursts yet, so I hope the
DMA will speed up those things, too.
Greets,
Clemens Koller
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next prev parent reply other threads:[~2005-07-01 7:47 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-06-30 15:12 MPC85xx DMA support for Kernel 2.6? Clemens Koller
2005-06-30 15:30 ` Kumar Gala
2005-06-30 15:56 ` Clemens Koller
2005-06-30 16:57 ` Murray.Jensen
2005-07-01 7:54 ` Clemens Koller
2005-07-01 8:36 ` Murray.Jensen
2005-07-01 13:59 ` Kumar Gala
2005-06-30 18:52 ` Dan Malek
2005-07-01 7:47 ` Clemens Koller [this message]
2005-07-01 14:02 ` Dan Malek
2005-07-01 14:15 ` Mark Chambers
2005-07-01 21:49 ` Dan Malek
2005-07-04 9:03 ` Clemens Koller
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