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=-2.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_NEOMUTT 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 EC7ECC10F14 for ; Tue, 23 Apr 2019 08:44:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AA7A820685 for ; Tue, 23 Apr 2019 08:44:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="uNPzXuPS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726569AbfDWIoQ (ORCPT ); Tue, 23 Apr 2019 04:44:16 -0400 Received: from mail-pf1-f194.google.com ([209.85.210.194]:33901 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725955AbfDWIoP (ORCPT ); Tue, 23 Apr 2019 04:44:15 -0400 Received: by mail-pf1-f194.google.com with SMTP id b3so7137527pfd.1; Tue, 23 Apr 2019 01:44:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=4BCmLrn9XjloUMHDFcLSGBgSblmX+pc4aRTHqZMNgSM=; b=uNPzXuPSuNlAX27x5umeqjkfmmvqx+KrVN+LRBNQSPtzR+SZIbLIcP1l0ve1LI+Cnf ONESixui6EBweKuJC9jgappYBXvchwm87qVXIrPlLPBOcQxYLtFOnf9YA5uU5GdDdD0J NDyOeJs13yxYE7KwxNXZPs94Kt/pMHSuNmDD9jUdWelE1TnEBxRzWYSDeWEzYjY9WbM8 J6oKp8U4ke1ZAKBT2s2iTuFOAzMGjuF3J4BoiKrSr1Zd4/49zLZaiOS9CQP2r0W2HX2W X/HzW+bmo37JJMqO/OSnN0Nxa+EoqmcF35g+iS7mc2YZP6eaRAf9agUQXHnSx06rKH42 muyw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=4BCmLrn9XjloUMHDFcLSGBgSblmX+pc4aRTHqZMNgSM=; b=LMcRcw144Vojr29XRs8gAX/n6PV+Uqp9YsE01CH/ltnZMZMWw8+sdqwfE8HDoKwQZS hVjRJDyCLQIWn9YM1o3nPlUg1sjaWGQiJfISmVcGeqekH5cdgOW8pWatMTMw18b2BLUg d3pqnT1d7CNpfe5TNXQY4Mhqg0vmXdIeF7VN2D+2HrGdpFhCUx9gc1ycAYPkzAU7ZQ86 vI/8pihdb7OGKyyoQkptVR6D/Rg+O9Z6I2+NDleVawm8R81CuP7SuMjq2GWIiAne8kWy 5FoZXdHluNmbLL/OXARVFmpkAC+QHNUEbuR7qhgIA7J+DACoxnoGuF00uNbfzdAthmQl rIrQ== X-Gm-Message-State: APjAAAWMnHBj5FcZdfzNh1v5xWg7QGM/QoIOflKHYt8B3zG1HYHguA51 bGPDtjesZDR+lq4KiWEM+b8= X-Google-Smtp-Source: APXvYqzQepngjZBl7cXxfzuQnonTn0bFcHmtfgE745U349AWrePtc8biWbCX49kiaK9+GLcJuh9TiQ== X-Received: by 2002:a65:6686:: with SMTP id b6mr23788734pgw.419.1556009054323; Tue, 23 Apr 2019 01:44:14 -0700 (PDT) Received: from localhost (p1962055-ipbf905funabasi.chiba.ocn.ne.jp. [118.15.107.55]) by smtp.gmail.com with ESMTPSA id b2sm19915034pfo.150.2019.04.23.01.44.13 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 23 Apr 2019 01:44:13 -0700 (PDT) Date: Tue, 23 Apr 2019 08:44:18 +0000 From: Dmitry Torokhov To: Kefeng Wang Cc: linux-kernel@vger.kernel.org, Masahiro Yamada , linux-input@vger.kernel.org Subject: Re: [PATCH next 09/25] input: keyboard: Use dev_get_drvdata() Message-ID: <20190423084418.sekqt5jeiqctvofe@penguin> References: <20190423075020.173734-1-wangkefeng.wang@huawei.com> <20190423075020.173734-10-wangkefeng.wang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190423075020.173734-10-wangkefeng.wang@huawei.com> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Kefeng, On Tue, Apr 23, 2019 at 03:50:04PM +0800, Kefeng Wang wrote: > Using dev_get_drvdata directly. This assumes that generic device's driver data is exactly the same as platform device's driver data. This is true today, but does not have to be true tomorrow. What is the benefit of violating the layering and accessing "parent" object's abstraction directly? Performance impact must be negligible... Thanks. -- Dmitry