From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22175C433E6 for ; Tue, 14 Jul 2020 16:08:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E697C2251E for ; Tue, 14 Jul 2020 16:08:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594742916; bh=m1sZU8ZEuecg3AdLYhlDX2E1cX3Y8hJyqEV30UQuGNU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=oHQ5LjcRUilx736kg0eGoKJL8X6lxa9WFBJkaCIGrI4mZ3NrItwD88KKBKpTPPJkL VAdY9pW9/AXaHXIeqrAVnQA5EjhuGabX7eSFt4arAQ5MBrSoJ/saraQqotSzKYIiho iIk05yKE16beBPIYw59krSg2JyFsnSCHzHknPP7I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726364AbgGNQIf (ORCPT ); Tue, 14 Jul 2020 12:08:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:39908 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725876AbgGNQIf (ORCPT ); Tue, 14 Jul 2020 12:08:35 -0400 Received: from localhost (unknown [122.171.202.192]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A3AE822515; Tue, 14 Jul 2020 16:08:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594742914; bh=m1sZU8ZEuecg3AdLYhlDX2E1cX3Y8hJyqEV30UQuGNU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=dYPw/QTslqDwXMkvcuWmgLjUlIp+8O6gOIUKVUY2+TlTa34zQ+zz1U09lJOwQW09S Zs39faJMF1AQ5iw8NUoRb+aOAmoaJq57/pNyE2didK61rX+fg7Upj2jbx+qnSqFSBo krdukl4duieXXuhukMg/55wm4P/zD5q7x9vpVeLg= Date: Tue, 14 Jul 2020 21:38:30 +0530 From: Vinod Koul To: Dave Jiang Cc: Serge Semin , Andy Shevchenko , Viresh Kumar , Dan Williams , Alexey Malahov , Thomas Bogendoerfer , Arnd Bergmann , Rob Herring , linux-mips@vger.kernel.org, devicetree@vger.kernel.org, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v7 05/11] dmaengine: Introduce DMA-device device_caps callback Message-ID: <20200714160830.GL34333@vkoul-mobl> References: <20200709224550.15539-1-Sergey.Semin@baikalelectronics.ru> <20200709224550.15539-6-Sergey.Semin@baikalelectronics.ru> <20200710084503.GE3703480@smile.fi.intel.com> <20200710093834.su3nsjesnhntpd6d@mobilestation> <07d4a977-1de6-b611-3d4f-7c7d6cd7fe5f@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <07d4a977-1de6-b611-3d4f-7c7d6cd7fe5f@intel.com> Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On 13-07-20, 13:55, Dave Jiang wrote: > > > On 7/10/2020 2:38 AM, Serge Semin wrote: > > On Fri, Jul 10, 2020 at 11:45:03AM +0300, Andy Shevchenko wrote: > > > On Fri, Jul 10, 2020 at 01:45:44AM +0300, Serge Semin wrote: > > > > There are DMA devices (like ours version of Synopsys DW DMAC) which have > > > > DMA capabilities non-uniformly redistributed between the device channels. > > > > In order to provide a way of exposing the channel-specific parameters to > > > > the DMA engine consumers, we introduce a new DMA-device callback. In case > > > > if provided it gets called from the dma_get_slave_caps() method and is > > > > able to override the generic DMA-device capabilities. > > > > > > > > In light of recent developments consider not to add 'slave' and a such words to the kernel. > > > > As long as the 'slave' word is used in the name of the dma_slave_caps > > structure and in the rest of the DMA-engine subsystem, it will be ambiguous > > to use some else terminology. If renaming needs to be done, then it should be > > done synchronously for the whole subsystem. > > What about just calling it dma_device_caps? Consider this is a useful > function not only slave DMA will utilize this. I can see this being useful > for some of my future code with idxd driver. Some of the caps may make sense to generic dmaengine but few of them do not :) While at it, am planning to make it dmaengine_periph_caps to denote that these are dmaengine peripheral capabilities. -- ~Vinod