From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lars-Peter Clausen Subject: Re: [PATCH, RFC] MIPS: jz4740: use dma filter function Date: Tue, 06 Jan 2015 13:51:50 +0100 Message-ID: <54ABDA66.7040002@metafoo.de> References: <22569458.nE7JkNNnz3@wuerfel> <54ABBCE6.8060904@metafoo.de> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-subscribe: List-owner: List-post: List-archive: To: =?windows-1252?Q?M=E5ns_Rullg=E5rd?= Cc: Arnd Bergmann , linux-kernel@vger.kernel.org, Ralf Baechle , dmaengine@vger.kernel.org, alsa-devel@alsa-project.org, linux-mmc@vger.kernel.org, linux-mips@linux-mips.org List-Id: alsa-devel@alsa-project.org On 01/06/2015 01:47 PM, M=E5ns Rullg=E5rd wrote: > Lars-Peter Clausen writes: > >> On 01/05/2015 11:39 PM, Arnd Bergmann wrote: >>> As discussed on the topic of shmobile DMA today, jz4740 is the only >>> user of the slave_id field in dma_slave_config besides shmobile. Th= is >>> use is really incompatible with the way that other drivers use the >>> dmaengine API, so we should get rid of it. >> >> Do you have a link to that discussion? >> >>> >>> This adds a trivial filter function that uses the filter param to >>> pass the dma type, and uses that in both drivers. >> >> In my opinion that's just from bad to worse. Using filter functions >> isn't that great in the first place. And using them to pass data fro= m >> the consumer to the DMA provider is just a horrible abuse of the API= =2E > > It seems to me the only sane way to use the dmaengine API is in > conjunction with DT. At the moment yes. For non DT we need something like the gpiod lookup t= ables=20 that allow you to specify the assignment of the DMA channel in the mach= ine=20 driver. - Lars