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 0FF09C54E8D for ; Mon, 11 May 2020 21:02:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E3E9824955 for ; Mon, 11 May 2020 21:02:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731935AbgEKVCD (ORCPT ); Mon, 11 May 2020 17:02:03 -0400 Received: from mga09.intel.com ([134.134.136.24]:46854 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732394AbgEKVCC (ORCPT ); Mon, 11 May 2020 17:02:02 -0400 IronPort-SDR: FxP6TRRGHphqbp6jDxLoZXUEBv25bZKRIqXHajCn3WHBWk128mbUQ7PDACgs+XU5z/s3GPVbLy +9OcQ7E2RpXg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 May 2020 14:01:39 -0700 IronPort-SDR: rm1hhYS517j4tRfG8qoVJZn+JTLquoo7K7+mgWFQddz7WgPeNX5R+Tvnm0hdl0TpEecMCJAPnB tXC7fyMLlgSA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,381,1583222400"; d="scan'208";a="463521700" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by fmsmga006.fm.intel.com with ESMTP; 11 May 2020 14:01:37 -0700 Received: from andy by smile with local (Exim 4.93) (envelope-from ) id 1jYFYQ-0063Cu-VM; Tue, 12 May 2020 00:01:38 +0300 Date: Tue, 12 May 2020 00:01:38 +0300 From: Andy Shevchenko To: Serge Semin Cc: Serge Semin , Vinod Koul , Viresh Kumar , Rob Herring , Alexey Malahov , Thomas Bogendoerfer , Paul Burton , Ralf Baechle , Arnd Bergmann , Dan Williams , linux-mips@vger.kernel.org, dmaengine@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 2/6] dt-bindings: dma: dw: Add max burst transaction length property Message-ID: <20200511210138.GN185537@smile.fi.intel.com> References: <20200306131048.ADBE18030797@mail.baikalelectronics.ru> <20200508105304.14065-1-Sergey.Semin@baikalelectronics.ru> <20200508105304.14065-3-Sergey.Semin@baikalelectronics.ru> <20200508111242.GH185537@smile.fi.intel.com> <20200511200528.nfkc2zkh3bvupn7l@mobilestation> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200511200528.nfkc2zkh3bvupn7l@mobilestation> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org 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: > > > This array property is used to indicate the maximum burst transaction > > > length supported by each DMA channel. > > > > > + snps,max-burst-len: > > > + $ref: /schemas/types.yaml#/definitions/uint32-array > > > + description: | > > > + Maximum length of burst transactions supported by hardware. > > > + It's an array property with one cell per channel in units of > > > + CTLx register SRC_TR_WIDTH/DST_TR_WIDTH (data-width) field. > > > + items: > > > + maxItems: 8 > > > + items: > > > > > + enum: [4, 8, 16, 32, 64, 128, 256] > > > > Isn't 1 allowed? > > Burst length of 1 unit is supported, but in accordance with Data Book the MAX > burst length is limited to be equal to a value from the set I submitted. So the > max value can be either 4, or 8, or 16 and so on. Hmm... It seems you mistakenly took here DMAH_CHx_MAX_MULT_SIZE pre-silicon configuration parameter instead of runtime as described in Table 26: CTLx.SRC_MSIZE and DEST_MSIZE Decoding. -- With Best Regards, Andy Shevchenko