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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 DFAA3C4CEC7 for ; Thu, 12 Sep 2019 17:04:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B4C18214AE for ; Thu, 12 Sep 2019 17:04:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568307863; bh=WfnIOTHHePxhKxrFtGHlrl53zHUSmfXSu0kmiCkwyOA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=T1ZOscd5TPJVeiSaXB+P8/D7JtZeja33XDeh3kMt/oUOVClySP+JyPhXwSUV6VUZJ xz0dmosfsG0xCrCetbwEi2mbD+2wxN8da3uZw8xv+grnI2H6wtkpZknVt7WEOKgqxI OCIMPt7+0yWJ1o0TbJZVOofPfApYr2j659oSsZtE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731089AbfILREU (ORCPT ); Thu, 12 Sep 2019 13:04:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:36470 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731067AbfILREU (ORCPT ); Thu, 12 Sep 2019 13:04:20 -0400 Received: from localhost (unknown [117.99.85.83]) (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 6CD0D2081B; Thu, 12 Sep 2019 17:04:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568307859; bh=WfnIOTHHePxhKxrFtGHlrl53zHUSmfXSu0kmiCkwyOA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mXNE/u6UvfnaDeSnwEVQ4IHgTnhUlCvp2ShHPoTKL+IFA3nrvHlOT5jYZlU/OfQll cS7hs8yK1pXOu+T2/iq5boJhLu95IfWeoTDi3dprf2uKYotdUHrxeYCoBLkTYTmbYO f0l06M5DZ+MY3A5TO2K3t2kPJ7CRwBLpeOBljp8o= Date: Thu, 12 Sep 2019 22:33:12 +0530 From: Vinod Koul To: Peter Ujfalusi Cc: robh+dt@kernel.org, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, dan.j.williams@intel.com, devicetree@vger.kernel.org Subject: Re: [RFC 1/3] dt-bindings: dma: Add documentation for DMA domains Message-ID: <20190912170312.GD4392@vkoul-mobl> References: <20190906141816.24095-1-peter.ujfalusi@ti.com> <20190906141816.24095-2-peter.ujfalusi@ti.com> <961d30ea-d707-1120-7ecf-f51c11c41891@ti.com> <20190908121058.GL2672@vkoul-mobl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On 09-09-19, 09:30, Peter Ujfalusi wrote: > >> or domain-dma-controller? > > > > I feel dma-domain-controller sounds fine as we are defining domains for > > dmaengine. Another thought which comes here is that why not extend this to > > slave as well and define dma-domain-controller for them as use that for > > filtering, that is what we really need along with slave id in case a > > specific channel is to be used by a peripheral > > > > Thoughts..? > > I have thought about this, we should be able to drop the phandle to the > dma controller from the slave binding just fine. > > However we have the dma routers for the slave channels and there is no > clear way to handle them. > They are not needed for non slave channels as there is no trigger to > route. In DRA7 for example we have an event router for EDMA and another > one for sDMA. If a slave device is to be serviced by EDMA, the EDMA > event router needs to be specified, for sDMA clients should use the sDMA > event router. So you have dma, xbar and client? And you need to use a specfic xbar, did i get that right? > In DRA7 case we don't really have DMA controllers for domains, but we > use the DMA which can service the peripheral better (sDMA is better to > be used for UART, but can not be used for McASP for example) > > Then we have the other type of DMA router for daVinci/am33xx/am43xx > where the crossbar is not for the whole EDMA controller like in DRA7, > but we have small crossbars for some channels. > > Other vendors have their own dma router topology.. > > Too many variables to handle the cases without gotchas, which would need > heavy churn in the core or in drivers. -- ~Vinod