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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 88676FD7072 for ; Tue, 17 Mar 2026 10:26:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=SzoWuglBUHqkpTQYCjp0o2fNxpGzsQXlIVffnZw0BsE=; b=uatJ/jRVRgm/DDO/Kz/i9OBbdq ORYojx56eID47KcDg1EsbSOZRvKj9Rl7KPfgQT0+rSgew3+m3Z41MveenHfbpnNIDvkD6ugonk67m 22w5ihXuWg54K/oehH/MLTvzsYcN7L8K+OoQaTL7yg92w6k0TQEQt3IfCKimHxqq1Kxc3USTlQA2W KSx0nDoxJHPjHg1+2kW5UZEtQt99OnUkBCxGMMdL+Ca2lKfi2Us4Is0rMZJATMfB6d8je+/9VWpXg boKI7UstueJgyasvEP9jIEOnXyWl2jZfsDJjLFYSJv9PBoFPn4Z8YP0571HGxh4cEg5MJLaGlxtpW HkEAqwtg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w2RdP-00000006143-2cRw; Tue, 17 Mar 2026 10:26:47 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1w2RdM-0000000613d-37VL for linux-arm-kernel@lists.infradead.org; Tue, 17 Mar 2026 10:26:45 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id AAB4140A09; Tue, 17 Mar 2026 10:26:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 150C7C4CEF7; Tue, 17 Mar 2026 10:26:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773743203; bh=leILco6ESwbAPx5/ChEkDeGOl9TARpFn5FFt7fhV91M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=EK+pGd/Qe+hHDmgY8MA52uxvkIPEOhyj8ZVsNmndCnSG5dr/RFkQ9EnPdTtgdc61H Cv1BQnZ3IDVErs0ElcARTaHFjSgtOIlIttxmykiFG8ScBTqIlcuYsDPneEBfXC7EYC Xkspxjnc6XfG8/+Gl8Htahhn2o+gOhHRob/jNy+0w4tkPw5+r5eNhsc1WethmBcvky xWXG2L5QQNS+FE1dYze7XpRzUc/frOLIjc4Nb3FErpzmNekXVc2Q/wMIWWsO/HxGE/ VcqQcQuMnZ8Of7QoctvtautlGcfI4NcN1sQiB7KTCaig1mVy2DW5gr/cfnhvZYZf5/ CxzWscbT1RSHQ== Date: Tue, 17 Mar 2026 15:56:40 +0530 From: Vinod Koul To: Frank Li Cc: Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 0/6] dmaengine: Add common dma_slave_config and split it into src and dst parts Message-ID: References: <20260114-dma_common_config-v1-0-64feb836ff04@nxp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260317_032644_820132_62FA7417 X-CRM114-Status: GOOD ( 17.49 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 09-03-26, 10:27, Frank Li wrote: > On Mon, Mar 09, 2026 at 12:24:33PM +0100, Vinod Koul wrote: > > On 14-01-26, 12:12, Frank Li wrote: > > > Many DMA engine drivers store a dma_slave_config per channel. Propagate > > > this configuration into struct dma_chan to avoid duplicating the same > > > code in each driver. > > > > > > Much of dma_slave_config is identical for source and destination. Split > > > the configuration into src and dst groups and use a union to preserve > > > backward compatibility. This reduces the need for drivers to repeatedly > > > check the DMA transfer direction. > > > > The reason why we had both the src/dstn sides was intended method to > > allow upport ofr device to device dma. Some interest was shown for that > > at that time. > > I dont think we have such a user even now... > > My means is the field name is identical, not value identical although most > case is the identical. but it is possible, especial FIFO space windows, > > sound/soc/fsl/fsl_asrc_dma.c use DEV_TO_DEV, at least src and addr use > differece address. Yeah so this would break if we go ahead. Thanks for looking this up -- ~Vinod