From mboxrd@z Thu Jan 1 00:00:00 1970 From: jassisinghbrar@gmail.com (jassi brar) Date: Thu, 18 Feb 2010 10:14:47 +0900 Subject: PL-330 DMA driver In-Reply-To: <63386a3d1002171353v36f7b5c8tdab15b1593581e02@mail.gmail.com> References: <1b68c6791002162150wb8fbae8ya1e5b3c0a56b7fad@mail.gmail.com> <63386a3d1002171026h51f34d4buc9ba0293ea08c004@mail.gmail.com> <20100217203114.GC30033@n2100.arm.linux.org.uk> <63386a3d1002171353v36f7b5c8tdab15b1593581e02@mail.gmail.com> Message-ID: <1b68c6791002171714u59a7d0fak7cd531de96eb0025@mail.gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Feb 18, 2010 at 6:53 AM, Linus Walleij wrote: > 2010/2/17 Guennadi Liakhovetski : > >> Of course, there's also a problem of reusing peripheral drivers with >> different DMA controllers... > > That's what I'm facing with MMCI and a host of other peripherals. > > We have to either: > > (1) Use something, i.e the DMA engine slave > > (2) Fork the driver entirely to some ste-mmci.c and delete all generic > ?code. (Repeat for each vendor using a primecell!) > > (3) Sprinkle mmci.c with #ifdef ARCH_U300 for our DMA engine. > ?Or, not so bad, atleast sprinkle the smallish part I have now > ?broken out in mmci.c that deals with DMA transfers. > > I think the current patch does (1) and it actually works, then if > it gets burdensome to others, using a generic DMA engine can > be a special case of (3) since that works for us so we're on the right > path in two cases and (2) doesn't look good to me. > > Yours, > Linus Walleij CCing the S3C maintainer (Ben Dooks) to share his opinion.