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 B981EC4708E for ; Tue, 3 Jan 2023 22:23:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238730AbjACWXB (ORCPT ); Tue, 3 Jan 2023 17:23:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43624 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238729AbjACWVn (ORCPT ); Tue, 3 Jan 2023 17:21:43 -0500 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [IPv6:2001:4d48:ad52:32c8:5054:ff:fe00:142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3350417409; Tue, 3 Jan 2023 14:20:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: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=ezBxF58/iYt4ytGREKmk4EHJi+NewNz9aFNzcPhEcYw=; b=Un/ZBjj4THLRJFaI3jBbBXkucy xUI45WocO2gEO94eHnU3fsLtEM94vFQJoIlVZX/9HlebD8cYZ7AqzkZbTzQyfpm0busc46Zl6wGIt orx2qJbtdDR/A1TDXLQ7OuLpdyKD1cZGfboGkfGZTaIqpEBt9qpW3+rKCOOc0Vaow2HK5bdhWWEC8 r5gDwaYGw4UWlrG6yIp6FVO6QyJLujP2p0BqvDTT/bJOW+4aVLyerujnJl7TQK2UWv/0/aekLlGsV YmDgPgPWpRE2fqy4vb9DmQJznADN+64HklkJ1Lop1Ji3UZM0WuswEq/SYcVpdud1/JF7ssBuVDZhL lBF6XAkQ==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:35956) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1pCpdY-0005wc-Hc; Tue, 03 Jan 2023 22:20:00 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1pCpdR-0002SM-O6; Tue, 03 Jan 2023 22:19:53 +0000 Date: Tue, 3 Jan 2023 22:19:53 +0000 From: "Russell King (Oracle)" To: Michael Walle Cc: Heiner Kallweit , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Jose Abreu , Sergey Shtylyov , Wei Fang , Shenwei Wang , Clark Wang , NXP Linux Team , Sean Wang , Landen Chao , DENG Qingfang , Florian Fainelli , Vladimir Oltean , Matthias Brugger , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Andrew Lunn , Geert Uytterhoeven Subject: Re: [PATCH RFC net-next v2 03/12] net: mdio: mdiobus_register: update validation test Message-ID: References: <20221227-v6-2-rc1-c45-seperation-v2-0-ddb37710e5a7@walle.cc> <20221227-v6-2-rc1-c45-seperation-v2-3-ddb37710e5a7@walle.cc> <37247c17e5e555dddbc37c3c63a2cadb@walle.cc> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <37247c17e5e555dddbc37c3c63a2cadb@walle.cc> Sender: Russell King (Oracle) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hi Michael, On Tue, Jan 03, 2023 at 11:21:08AM +0100, Michael Walle wrote: > Hi Russell, > > Am 2023-01-03 11:13, schrieb Russell King (Oracle): > > On Wed, Dec 28, 2022 at 12:07:19AM +0100, Michael Walle wrote: > > > + if (!bus || !bus->name) > > > + return -EINVAL; > > > + > > > + /* An access method always needs both read and write operations */ > > > + if ((bus->read && !bus->write) || > > > + (!bus->read && bus->write) || > > > + (bus->read_c45 && !bus->write_c45) || > > > + (!bus->read_c45 && bus->write_c45)) > > > > I wonder whether the following would be even more readable: > > > > if (!bus->read != !bus->write || !bus->read_c45 != !bus->write_c45) > > That's what Andrew had originally. But there was a comment from Sergey [1] > which I agree with. I had a hard time wrapping my head around that, so I > just listed all the possible bad cases. The only reason I suggested it was because when looked at your code, it also took several reads to work out what it was trying to do! Would using !!bus->read != !!bus->write would help or make it worse, !!ptr being the more normal way to convert something to a boolean? -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!