From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Fri, 31 May 2013 18:02:31 +0200 Subject: [PATCH 1/2] ARM: shmobile: sdhi: pass DMA filter from platform code In-Reply-To: References: <1370008605-3745603-1-git-send-email-arnd@arndb.de> <2862988.jnTv0iSQcj@wuerfel> Message-ID: <3675801.kLfsmmiSOq@wuerfel> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Friday 31 May 2013 17:30:01 Guennadi Liakhovetski wrote: > On Fri, 31 May 2013, Arnd Bergmann wrote: > > On Friday 31 May 2013 16:52:13 Guennadi Liakhovetski wrote: > > 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 Yes, those should be fixed as well. > And what do you do for DT-based platforms? Once the driver is DT-enabled, we no longer have to pass a filter function at all because the slave id and all settings will get pulled out of the DT using the dma engine's xlate() callback. Arnd