From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH v6 03/10] ARM: edma: add AM33XX support to the private EDMA API Date: Thu, 31 Jan 2013 20:58:39 +0000 Message-ID: <201301312058.39948.arnd@arndb.de> References: <1359529229-22207-1-git-send-email-mporter@ti.com> <201301300932.58732.arnd@arndb.de> <20130131183255.GI2244@beef> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130131183255.GI2244@beef> Sender: linux-doc-owner@vger.kernel.org To: Matt Porter Cc: Linux DaVinci Kernel List , Linux OMAP List , Russell King , Benoit Cousson , Linux Documentation List , Tony Lindgren , Linux MMC List , Devicetree Discuss , Mark Brown , Linux Kernel Mailing List , Rob Herring , Grant Likely , Vinod Koul , Rob Landley , Dan Williams , Padma Venkat , Linux SPI Devel List , Chris Ball , Linux ARM Kernel List List-Id: linux-mmc@vger.kernel.org On Thursday 31 January 2013, Matt Porter wrote: > On Wed, Jan 30, 2013 at 09:32:58AM +0000, Arnd Bergmann wrote: > > On Wednesday 30 January 2013, Matt Porter wrote: > > > + dma_cap_set(DMA_SLAVE, edma_filter_info.dma_cap); > > > + of_dma_controller_register(dev->of_node, > > > + of_dma_simple_xlate, > > > + &edma_filter_info); > > > + } > > > > How do you actually deal with the problem mentioned by Padma, that > > the filter function does not know which edma instance it is looking > > at? If you assume that there can only be a single edma instance in > > the system, that is probably a limitation that should be documented > > somewhere, and ideally the probe() function should check for that. > > I make an assumption of one edma instance in the system in the case of > DT being populated. This is always true right now as the only SoC with > two EDMA controllers in existence is Davinci DA850. Until recently, > Davinci had no DT support. Given the steady work being done today on DT > support for DA850, it'll probably be something needed in 3.10. > > I will add a comment and check in probe() to capture this assumption > and then plan to update separately to support DA850 booting from DT. Ok, sounds good. Hopefully by then we will already have a nicer way to write an xlate function that does not rely on a filter function. Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Thu, 31 Jan 2013 20:58:39 +0000 Subject: [PATCH v6 03/10] ARM: edma: add AM33XX support to the private EDMA API In-Reply-To: <20130131183255.GI2244@beef> References: <1359529229-22207-1-git-send-email-mporter@ti.com> <201301300932.58732.arnd@arndb.de> <20130131183255.GI2244@beef> Message-ID: <201301312058.39948.arnd@arndb.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thursday 31 January 2013, Matt Porter wrote: > On Wed, Jan 30, 2013 at 09:32:58AM +0000, Arnd Bergmann wrote: > > On Wednesday 30 January 2013, Matt Porter wrote: > > > + dma_cap_set(DMA_SLAVE, edma_filter_info.dma_cap); > > > + of_dma_controller_register(dev->of_node, > > > + of_dma_simple_xlate, > > > + &edma_filter_info); > > > + } > > > > How do you actually deal with the problem mentioned by Padma, that > > the filter function does not know which edma instance it is looking > > at? If you assume that there can only be a single edma instance in > > the system, that is probably a limitation that should be documented > > somewhere, and ideally the probe() function should check for that. > > I make an assumption of one edma instance in the system in the case of > DT being populated. This is always true right now as the only SoC with > two EDMA controllers in existence is Davinci DA850. Until recently, > Davinci had no DT support. Given the steady work being done today on DT > support for DA850, it'll probably be something needed in 3.10. > > I will add a comment and check in probe() to capture this assumption > and then plan to update separately to support DA850 booting from DT. Ok, sounds good. Hopefully by then we will already have a nicer way to write an xlate function that does not rely on a filter function. Arnd