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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 E758FC433DF for ; Fri, 15 May 2020 11:11:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C9688206B6 for ; Fri, 15 May 2020 11:11:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726046AbgEOLLR (ORCPT ); Fri, 15 May 2020 07:11:17 -0400 Received: from mail.baikalelectronics.com ([87.245.175.226]:36082 "EHLO mail.baikalelectronics.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726037AbgEOLLR (ORCPT ); Fri, 15 May 2020 07:11:17 -0400 Received: from localhost (unknown [127.0.0.1]) by mail.baikalelectronics.ru (Postfix) with ESMTP id 44F708029EC9; Fri, 15 May 2020 11:11:14 +0000 (UTC) X-Virus-Scanned: amavisd-new at baikalelectronics.ru Received: from mail.baikalelectronics.ru ([127.0.0.1]) by localhost (mail.baikalelectronics.ru [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 54LBlF8pMoKn; Fri, 15 May 2020 14:11:13 +0300 (MSK) Date: Fri, 15 May 2020 14:11:12 +0300 From: Serge Semin To: Vinod Koul CC: Serge Semin , Andy Shevchenko , Viresh Kumar , Rob Herring , Alexey Malahov , Thomas Bogendoerfer , Paul Burton , Ralf Baechle , Arnd Bergmann , Dan Williams , , , , Subject: Re: [PATCH v2 2/6] dt-bindings: dma: dw: Add max burst transaction length property Message-ID: <20200515111112.4umynrpgzjnca223@mobilestation> References: <20200508111242.GH185537@smile.fi.intel.com> <20200511200528.nfkc2zkh3bvupn7l@mobilestation> <20200511210138.GN185537@smile.fi.intel.com> <20200511213531.wnywlljiulvndx6s@mobilestation> <20200512090804.GR185537@smile.fi.intel.com> <20200512114946.x777yb6bhe22ccn5@mobilestation> <20200512123840.GY185537@smile.fi.intel.com> <20200515060911.GF333670@vkoul-mobl> <20200515105137.GK185537@smile.fi.intel.com> <20200515105658.GR333670@vkoul-mobl> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20200515105658.GR333670@vkoul-mobl> X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On Fri, May 15, 2020 at 04:26:58PM +0530, Vinod Koul wrote: > On 15-05-20, 13:51, Andy Shevchenko wrote: > > On Fri, May 15, 2020 at 11:39:11AM +0530, Vinod Koul wrote: > > > On 12-05-20, 15:38, Andy Shevchenko wrote: > > > > On Tue, May 12, 2020 at 02:49:46PM +0300, Serge Semin wrote: > > > > > On Tue, May 12, 2020 at 12:08:04PM +0300, Andy Shevchenko wrote: > > > > > > On Tue, May 12, 2020 at 12:35:31AM +0300, Serge Semin wrote: > > > > > > > On Tue, May 12, 2020 at 12:01:38AM +0300, Andy Shevchenko wrote: > > > > > > > > On Mon, May 11, 2020 at 11:05:28PM +0300, Serge Semin wrote: > > > > > > > > > On Fri, May 08, 2020 at 02:12:42PM +0300, Andy Shevchenko wrote: > > > > > > > > > > On Fri, May 08, 2020 at 01:53:00PM +0300, Serge Semin wrote: > > > > ... > > > > > > I leave it to Rob and Vinod. > > > > It won't break our case, so, feel free with your approach. > > > > > > I agree the DT is about describing the hardware and looks like value of > > > 1 is not allowed. If allowed it should be added.. > > > > It's allowed at *run time*, it's illegal in *pre-silicon stage* when > > synthesizing the IP. > > Then it should be added .. Vinod, max-burst-len is "MAXimum" burst length not "run-time or current or any other" burst length. It's a constant defined at the IP-core synthesis stage and according to the Data Book, MAX burst length can't be 1. The allowed values are exactly as I described in the binding [4, 8, 16, 32, ...]. MAX burst length defines the upper limit of the run-time burst length. So setting it to 1 isn't about describing a hardware, but using DT for the software convenience. -Sergey > > -- > ~Vinod