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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 C1C18C76194 for ; Wed, 24 Jul 2019 16:39:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9B35A2189F for ; Wed, 24 Jul 2019 16:39:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="1nfk9Ah7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387523AbfGXQjM (ORCPT ); Wed, 24 Jul 2019 12:39:12 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:34874 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387474AbfGXQjM (ORCPT ); Wed, 24 Jul 2019 12:39:12 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=wArjT2MpImAqGdQUdIABnoJnGCq4fg+a4RGyelO4sI0=; b=1nfk9Ah7W9jraNjNJyLYk5qygW c9Is3PaSspG/UF2r8LD3z1th+dBaZFXBAS8ftFOF9l0fbKVOPLzk2ihr9UuPdG3XhlVck4uPxHxkL 4EfXWn/h2ZoD9K6g5WQiAB4HTbsDrPvyERusX4xONbN/aKjx+fwRzVl/EkQhsO3z805I=; Received: from andrew by vps0.lunn.ch with local (Exim 4.89) (envelope-from ) id 1hqKIE-0000gj-4j; Wed, 24 Jul 2019 18:39:06 +0200 Date: Wed, 24 Jul 2019 18:39:06 +0200 From: Andrew Lunn To: Claudiu Manoil Cc: "David S . Miller" , Rob Herring , Leo Li , Alexandru Marginean , "netdev@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH net-next v1 1/4] enetc: Clean up local mdio bus allocation Message-ID: <20190724163906.GT25635@lunn.ch> References: <1563979301-596-1-git-send-email-claudiu.manoil@nxp.com> <1563979301-596-2-git-send-email-claudiu.manoil@nxp.com> <20190724151803.GR25635@lunn.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org > >All the horrible casts go away, the driver is structured like every > >other driver, sparse is probably happy, etc. > > > > This looks more like a matter cosmetic preferences. I mean, I didn't > notice anything "horrible" in the code so far. #define bus_to_enetc_regs(bus) (struct enetc_mdio_regs __iomem *)((bus)->priv) You should not need a cast here, bus->priv is a void *. But bus->priv is being abused to hold a __iomem pointer. enetc_wr_reg(®s->mdio_cfg, mdio_cfg); This is also rather odd, passing the address of something to an IO operator? I also don't know the C standard well enough to know if it is guaranteed that: struct enetc_mdio_regs { u32 mdio_cfg; /* MDIO configuration and status */ u32 mdio_ctl; /* MDIO control */ u32 mdio_data; /* MDIO data */ u32 mdio_addr; /* MDIO address */ }; actually works. On a 64bit system is the compiler allowed to put in padding to keep the u32 64 bit aligned? > I actually find it more > ugly to define a new structure with only one element inside, like: > struct enetc_mdio_priv { > struct enetc_hw *hw; > } One advantage of this is that struct enetc_hw correctly has all the __iomem attributes. All the casts to __iomem go away, and sparse is happy. > Anyway, if others already did this in the kernel, what can I do? Clean it up. Make the code more readable and easy to maintain. Andrew