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=-3.8 required=3.0 tests=BAYES_00, 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 E1DC4C64E75 for ; Mon, 23 Nov 2020 10:22:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8E1572074B for ; Mon, 23 Nov 2020 10:22:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728241AbgKWKV5 (ORCPT ); Mon, 23 Nov 2020 05:21:57 -0500 Received: from mga07.intel.com ([134.134.136.100]:13889 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728177AbgKWKV5 (ORCPT ); Mon, 23 Nov 2020 05:21:57 -0500 IronPort-SDR: aPE8N6gKOTojOmbxUxZrWrTVCOdt0EIESBgrA0I30BRHfp4JdxRnRtsjBZwup/GMhZt6HAL5BX chnnyBTF5U9w== X-IronPort-AV: E=McAfee;i="6000,8403,9813"; a="235879373" X-IronPort-AV: E=Sophos;i="5.78,363,1599548400"; d="scan'208";a="235879373" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Nov 2020 02:21:56 -0800 IronPort-SDR: bDYcC0KazFEg8m1ptN73iHBFmsa13wxflaQanQLsw0kHHkwlR1mXimKGt/uNf9/QIGiAh2fjlu dlnEAr6WbTPw== X-IronPort-AV: E=Sophos;i="5.78,363,1599548400"; d="scan'208";a="536051793" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Nov 2020 02:21:54 -0800 Received: from andy by smile with local (Exim 4.94) (envelope-from ) id 1kh8zo-0097fC-RX; Mon, 23 Nov 2020 12:22:56 +0200 Date: Mon, 23 Nov 2020 12:22:56 +0200 From: Andy Shevchenko To: Sia Jee Heng Cc: vkoul@kernel.org, Eugeniy.Paltsev@synopsys.com, robh+dt@kernel.org, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Subject: Re: [PATCH v5 16/16] dmaengine: dw-axi-dmac: Virtually split the linked-list Message-ID: <20201123102256.GV4077@smile.fi.intel.com> References: <20201123023452.7894-1-jee.heng.sia@intel.com> <20201123023452.7894-17-jee.heng.sia@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201123023452.7894-17-jee.heng.sia@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 23, 2020 at 10:34:52AM +0800, Sia Jee Heng wrote: > AxiDMA driver exposed the dma_set_max_seg_size() to the DMAENGINE. > It shall helps the DMA clients to create size-optimized linked-list > for the controller. > > However, there are certain situations where DMA client might not be > abled to benefit from the dma_get_max_seg_size() if the segment size > can't meet the nature of the DMA client's operation. > > In the case of ALSA operation, ALSA application and driver expecting > to run in a period of larger than 10ms regardless of the bit depth. > With this large period, there is a strong request to split the linked-list > in the AxiDMA driver. I'm wondering why ASoC generic code can't use DMA channel and device capabilities and prepare SG list with all limitations taken into account. -- With Best Regards, Andy Shevchenko