From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751951Ab2CIJYh (ORCPT ); Fri, 9 Mar 2012 04:24:37 -0500 Received: from moutng.kundenserver.de ([212.227.17.9]:57337 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751014Ab2CIJYe (ORCPT ); Fri, 9 Mar 2012 04:24:34 -0500 Date: Fri, 9 Mar 2012 10:24:29 +0100 (CET) From: Guennadi Liakhovetski X-X-Sender: lyakh@axis700.grange To: Vinod Koul cc: Russell King - ARM Linux , linux-kernel@vger.kernel.org, "'Jassi Brar'" , Linus Walleij , Magnus Damm , Paul Mundt Subject: Re: [PATCH/RFC] dmaengine: add a slave parameter to __dma_request_channel() In-Reply-To: <1331284918.4657.69.camel@vkoul-udesk3> Message-ID: References: <1331101687.24656.319.camel@vkoul-udesk3> <20120307093026.GM17370@n2100.arm.linux.org.uk> <20120307103112.GP17370@n2100.arm.linux.org.uk> <20120307124620.GT17370@n2100.arm.linux.org.uk> <20120307142634.GA18787@n2100.arm.linux.org.uk> <20120307162755.GB18787@n2100.arm.linux.org.uk> <1331188201.4657.51.camel@vkoul-udesk3> <1331204128.4657.54.camel@vkoul-udesk3> <1331206459.4657.59.camel@vkoul-udesk3> <1331211513.4657.67.camel@vkoul-udesk3> <1331284918.4657.69.camel@vkoul-udesk3> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Provags-ID: V02:K0:uefk2pclQXjw5nEvfea9xBQykvULZ4wzpUtdun37ZzE SjLJquW+vNxHrsZ51pOEu9MtxCPHxvyHzJzUENjr5MkVM2otTQ yXgxK9VpJzy2n9yHRsjxzPnVii5EPcGwW4YbKTvtJjCyok4c0w qN9FXe6Sl6xun1fZepjxtHcltQz+aRoRt+wECtZiHN77MxI1dE LPfBwgHtO/2EuOJX6aPbsj7uNZGZ0dHzz555I1NjGLwBWMAe+w ObVLtxvjE9QK5QdIsaHJSBn2rEfEHKl2SzRiAareSS40t4NMo1 JTArrjeYkHPrBhQHkMzhE5zuOJWq1HvTGP04JOs/4i5I4fE5G0 UCj3x1T8EJ5tq8PMVOiOLpdUR2VyGurmfVseI/PbjDL2MT36Hb mpJJP0uuMdaPQ== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 9 Mar 2012, Vinod Koul wrote: > On Thu, 2012-03-08 at 14:18 +0100, Guennadi Liakhovetski wrote: > > > Assuming I didn't miss... > > > > > > The case B can be handled without sweat by platforms channel mapping > > > information. > > > > > > Case A where we don't find that devices exist in map, thus being treated > > > as generic DMA channels and can be handled easily in sequence. So when > > > someone in Q request a channel it would get first channel in Ps > > > > > > This way we handle both of them in a transparent manner to both clients > > > and controllers. > > > > > > Perhaps we can also add capability to know that if channel is to be > > > searched in map or not - would be anyway required for non slave cases. > > > > Right, but I don't understand then what this gives us. You propose some > > channel maps, that will not be used for your "case A." Which means, for > > "case A" nothing changes. So, the reason for this whole thread hasn't been > > addressed: how to pass channel configuration to the DMA controller driver. > For "Case A" there should be no filtering or any issues even now. You > have controller requesting a channel and as long as they get a channel > for respective pool, it should work. > > Or is there anything else which is required in this case? Yes, there is. You keep complaining about my use of .priv pointer, which I use in the filter to pass channel configuration to the DMA controller driver. That is the original reason for this whole discussion. If you're fine with that, I'll just carry that .priv use over in the "simple" DMA engine driver and stay happy forever:-) Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/