From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752417AbbCHLVf (ORCPT ); Sun, 8 Mar 2015 07:21:35 -0400 Received: from smtp-out-138.synserver.de ([212.40.185.138]:1133 "EHLO smtp-out-138.synserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752303AbbCHLVe (ORCPT ); Sun, 8 Mar 2015 07:21:34 -0400 X-SynServer-TrustedSrc: 1 X-SynServer-AuthUser: lars@metafoo.de X-SynServer-PPID: 11927 Message-ID: <54FC30BE.1070606@metafoo.de> Date: Sun, 08 Mar 2015 12:21:34 +0100 From: Lars-Peter Clausen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.5.0 MIME-Version: 1.0 To: Andy Shevchenko , Mark Brown CC: Stanimir Varbanov , "linux-kernel@vger.kernel.org" , linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-spi@vger.kernel.org, Rob Herring , Mark Rutland , Kumar Gala , Andy Gross , Sagar Dharia , Daniel Sneddon Subject: Re: [PATCH v4] spi: qup: Add DMA capabilities References: <1425463325-25805-1-git-send-email-stanimir.varbanov@linaro.org> <20150307112109.GJ28806@sirena.org.uk> In-Reply-To: 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 03/07/2015 08:43 PM, Andy Shevchenko wrote: > On Sat, Mar 7, 2015 at 1:21 PM, Mark Brown wrote: >> On Wed, Mar 04, 2015 at 12:02:05PM +0200, Stanimir Varbanov wrote: >>> From: Andy Gross >>> >>> This patch adds DMA capabilities to the spi-qup driver. If DMA channels are >>> present, the QUP will use DMA instead of block mode for transfers to/from SPI >>> peripherals for transactions larger than the length of a block. >> >> Applied, but why is there no devm_dma_request_slave_channel_reason()? > > I suppose the answer would be "we have a lot of slightly different > cases and we have to get rid of current mess with legacy API calls". > The most problematic stuff now inside DMA slave subsystem is so called > "filter function". It's a main impediment right now as I understand. dma_request_slave_channel_reason() is the sane API though and does not use the filter functions. Adding a devm version of it seems reasonable. - Lars