From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754777AbbAFKqE (ORCPT ); Tue, 6 Jan 2015 05:46:04 -0500 Received: from smtp-out-090.synserver.de ([212.40.185.90]:1060 "EHLO smtp-out-090.synserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751098AbbAFKqC (ORCPT ); Tue, 6 Jan 2015 05:46:02 -0500 X-SynServer-TrustedSrc: 1 X-SynServer-AuthUser: lars@metafoo.de X-SynServer-PPID: 31907 Message-ID: <54ABBCE6.8060904@metafoo.de> Date: Tue, 06 Jan 2015 11:45:58 +0100 From: Lars-Peter Clausen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.3.0 MIME-Version: 1.0 To: Arnd Bergmann CC: 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 Subject: Re: [PATCH, RFC] MIPS: jz4740: use dma filter function References: <22569458.nE7JkNNnz3@wuerfel> In-Reply-To: <22569458.nE7JkNNnz3@wuerfel> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. This > 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 from the consumer to the DMA provider is just a horrible abuse of the API. The patch also adds a platform dependency, so the drivers won't built with COMPILE_TEST anymore. - Lars