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_PASS autolearn=ham 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 12F7EC43142 for ; Wed, 27 Jun 2018 09:09:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C28B723F36 for ; Wed, 27 Jun 2018 09:09:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C28B723F36 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lucaceresoli.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934039AbeF0JJn (ORCPT ); Wed, 27 Jun 2018 05:09:43 -0400 Received: from srv-hp10-72.netsons.net ([94.141.22.72]:50555 "EHLO srv-hp10-72.netsons.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751114AbeF0JJk (ORCPT ); Wed, 27 Jun 2018 05:09:40 -0400 Received: from [109.168.11.45] (port=55870 helo=[192.168.101.172]) by srv-hp10.netsons.net with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.91) (envelope-from ) id 1fY5Zi-00490X-OY; Wed, 27 Jun 2018 10:13:15 +0200 Subject: Re: [PATCH v4 6/8] media: imx274: add helper function to fill a reg_8 table chunk To: Sakari Ailus Cc: linux-media@vger.kernel.org, Sakari Ailus , Leon Luo , Mauro Carvalho Chehab , linux-kernel@vger.kernel.org References: <1528716939-17015-1-git-send-email-luca@lucaceresoli.net> <1528716939-17015-7-git-send-email-luca@lucaceresoli.net> <20180626122053.gd5jmt2wr35s5oh2@valkosipuli.retiisi.org.uk> From: Luca Ceresoli Message-ID: Date: Wed, 27 Jun 2018 10:13:12 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <20180626122053.gd5jmt2wr35s5oh2@valkosipuli.retiisi.org.uk> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - srv-hp10.netsons.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - lucaceresoli.net X-Get-Message-Sender-Via: srv-hp10.netsons.net: authenticated_id: luca@lucaceresoli.net X-Authenticated-Sender: srv-hp10.netsons.net: luca@lucaceresoli.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Sakari, On 26/06/2018 14:20, Sakari Ailus wrote: > Hi Luca, > > On Mon, Jun 11, 2018 at 01:35:37PM +0200, Luca Ceresoli wrote: >> Tables of struct reg_8 are used to simplify multi-byte register >> assignment. However filling these snippets with values computed at >> runtime is currently implemented by very similar functions doing the >> needed shift & mask manipulation. >> >> Replace all those functions with a unique helper function to fill >> reg_8 tables in a simple and clean way. > > What's the purpose of writing these registers as multiple I²C writes, when > this can be done as a single write (i.e. the address followed by two or > three octets of data)? Good point. The for loops applying the register values (the lines just after those changed by my patch) defuse the regmap bulk write capability. I guess this could be improved not filling any table, but directly calling regmap_bulk_write(), passing the u16 or u32 register value with proper endianness. No tables, less code. This would replace the present patch with a shorter and more effective one. Is it what you was suggesting? I'll try that. -- Luca