From mboxrd@z Thu Jan 1 00:00:00 1970 From: g.liakhovetski@gmx.de (Guennadi Liakhovetski) Date: Fri, 31 May 2013 17:30:01 +0200 (CEST) Subject: [PATCH 1/2] ARM: shmobile: sdhi: pass DMA filter from platform code In-Reply-To: <2862988.jnTv0iSQcj@wuerfel> References: <1370008605-3745603-1-git-send-email-arnd@arndb.de> <2862988.jnTv0iSQcj@wuerfel> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, 31 May 2013, Arnd Bergmann wrote: > On Friday 31 May 2013 16:52:13 Guennadi Liakhovetski wrote: > > > > Thanks for the patches. How about this fix: > > > > http://thread.gmane.org/gmane.linux.kernel.mmc/20619 > > > > I think it's a better fix. SHDMA users cannot use other DMA drivers, so, I > > don't think we need to pass the filter via the platform data. > > I think it's more a matter of using the API correctly. The dmaengine > API is an abstraction to separate the slave driver from the master > through well-defined calls. If you make additional assumptions > in the slave driver about the master, that is a layering violation. I think it is a common practice, see e.g. drivers/mmc/host/omap_hsmmc.c drivers/mmc/host/davinci_mmc.c And what do you do for DT-based platforms? Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/