From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.genesi-usa.com (mithrandir.softwarenexus.net [66.98.186.96]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 3F0F1DDEF1 for ; Mon, 25 Jun 2007 21:36:23 +1000 (EST) Message-ID: <467FA0EA.3000607@genesi-usa.com> Date: Mon, 25 Jun 2007 12:03:06 +0100 From: Matt Sealey MIME-Version: 1.0 To: Arnd Bergmann Subject: Re: Mem-2-Mem DMA - Generalized API References: <20070624193932.GA11797@clifford.at> <200706242221.57507.arnd@arndb.de> In-Reply-To: <200706242221.57507.arnd@arndb.de> Content-Type: text/plain; charset=UTF-8 Cc: linuxppc-embedded@ozlabs.org List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , IOAT and Intel's DMA engine driver is very IOAT specific in places.. I had a peek at it as I have a little interest in the concept; at least the two platforms Genesi has been supporting (Pegasos and Efika) have quite competant DMA engines which are woefully underused (i.e. not at all). There exists a Marvell DMA driver somewhere (I have a copy, someone on this list posted it about a year ago) and while the MPC5200B doesn't have explicit support for DMA from memory to memory (although memory to SRAM might work in chunks, or memory to a FIFO wired as a loopback like in the docs..??) There is so much you can do with most SoC DMA controllers, and it's not even limited to PowerPC (most ARM/XScale SoCs have very capable devices inside too). I can only imagine that nobody got excited over IOAT because the entire programming interface stinks of "offloading gigabit ethernet" and not much else. -- Matt Sealey Genesi, Manager, Developer Relations Arnd Bergmann wrote: > On Sunday 24 June 2007, Clifford Wolf wrote: >> I'm working on an MPC8349E based project and as some of you might know this >> chip has a four channel (bus-) memory-to-memory DMA controller. >> >> Unfortunately the linux kernel is atm lacking a generic interface for such >> DMA controllers. > > So what's wrong with the include/linux/dmaengine.h API? I thought it was > designed to cover this sort of DMA controller? > > Arnd <>< > _______________________________________________ > Linuxppc-embedded mailing list > Linuxppc-embedded@ozlabs.org > https://ozlabs.org/mailman/listinfo/linuxppc-embedded