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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4050FC677F1 for ; Thu, 12 Jan 2023 20:50:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240245AbjALUuU (ORCPT ); Thu, 12 Jan 2023 15:50:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51972 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234267AbjALUtx (ORCPT ); Thu, 12 Jan 2023 15:49:53 -0500 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C282C7FEF0 for ; Thu, 12 Jan 2023 12:19:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1673554771; x=1705090771; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=xPz0ZPBEZzdOTN1uk31DLN4iVs/QuDCfz3K5QzwOKkE=; b=Gte0HBq0rdVlC4TNkjvqNOQe5NGmQjv/4gbj8RTq5JbBDhFDx8ehqea5 FCkTezi7/0E8QVKy2++OuSY9JtPJXcE2XbumWojq7MOu20XsmIZVNcwpS zoLR965VKr6vcdTL1SJKFFXSwTOT6dhccIvJuyaGQNQABmpKet5ZDi/xa c8CZJVY7wNuvTcloXNhg4Fm6ybd5Ym2naOaQCRaqVUTTrXMNYRTuu+2VI Z4oNYbWgtQP4VnGyVYTG6SkQst3TIiwtHlwP6D8RjUW+bJzhBFdFilvnY 0xfzZwTHvmbJ/qNMlDKbl4xkZNCdf133DDAIjZ7kAyws2Rb+cnVKIOEMg w==; X-IronPort-AV: E=McAfee;i="6500,9779,10588"; a="304201857" X-IronPort-AV: E=Sophos;i="5.97,211,1669104000"; d="scan'208";a="304201857" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2023 12:19:30 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10588"; a="659968451" X-IronPort-AV: E=Sophos;i="5.97,211,1669104000"; d="scan'208";a="659968451" Received: from jcalle-mobl.amr.corp.intel.com (HELO [10.209.179.77]) ([10.209.179.77]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2023 12:19:30 -0800 Message-ID: <4a6ae9b4-2748-c751-aec6-05979de95cfe@linux.intel.com> Date: Thu, 12 Jan 2023 14:19:29 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Firefox/102.0 Thunderbird/102.4.2 Subject: Re: [PATCH 2/2] regmap: sdw: Remove 8-bit value size restriction Content-Language: en-US To: Mark Brown Cc: Charles Keepax , vkoul@kernel.org, yung-chuan.liao@linux.intel.com, sanyog.r.kale@intel.com, linux-kernel@vger.kernel.org, patches@opensource.cirrus.com References: <20230112171840.2098463-1-ckeepax@opensource.cirrus.com> <20230112171840.2098463-3-ckeepax@opensource.cirrus.com> <756fcb2d-d571-18cb-985e-d907ab682275@linux.intel.com> <3320e6b8-28c7-d028-3c4c-2b4b25a963fb@linux.intel.com> From: Pierre-Louis Bossart In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/12/23 13:50, Mark Brown wrote: > On Thu, Jan 12, 2023 at 12:43:46PM -0600, Pierre-Louis Bossart wrote: >> On 1/12/23 12:14, Mark Brown wrote: > >>> The regmap gather_write() operation allows the bus to take two buffers, >>> one for the register and one for the value, rather than requiring the >>> core combine everything into a single buffer (mainly useful for large >>> transfers like firmware downloads). > >> Right, but that's not supported in SoundWire. sdw_nwrite() will only >> work with consecutive addresses - and the auto-increment is handled in >> software, not hardware. > > No, that's exactly what this is for. It's for the *register address* > being in a separate buffer, the data is then a sequence of consecutive > register values.> >> What's suggested here is to use the first element of reg_buf, which begs >> the question how different this is from a regular write. If there was a >> discontinuity in reg_buf then this wouldn't work at all. > > reg_buf contains the address of exactly one register. So what's the difference with a plain write() of N data?