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=-5.1 required=3.0 tests=BAYES_00,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 712C9C43460 for ; Fri, 14 May 2021 13:09:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 40B9B61451 for ; Fri, 14 May 2021 13:09:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230034AbhENNK0 (ORCPT ); Fri, 14 May 2021 09:10:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34512 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230306AbhENNKY (ORCPT ); Fri, 14 May 2021 09:10:24 -0400 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 5F291C06174A; Fri, 14 May 2021 06:09:13 -0700 (PDT) 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=BXqAC1pbKs3j4NOO8yWXGrt0LNNTBr4iLV2yAP7ms80=; b=OgwWUSq1igQM+qijDhyiGpZbB 7pJhTLrdVnAZ5DZ3iS5WTWxGeL+xy8flu9DxXz2OkAC+kU5Vf/DMusm6P3V9sMJSWrz4SqgBJeFTU fmI8iThYjOUYoR7z3wz+2xklLyju2B9NLCEQi09WwkXwo4BRs3k3O5BnAnl6/mK0Vak55wjvlKEHR O91YCtVgJcoS/7vJOzu4DkGu5iTk/x9u/UNK8QvK47UO1m1TcIuG8Wdmuh97HFjzNCxpxy6RU5EBF npNVpKRklFtY0KrDX597FXumGg26Id1krUVYbQ2hrBo4LCA8lkivL1pmswzIKPnNVI30X3enx4uS9 El6wrBUFA==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:43972) by pandora.armlinux.org.uk with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lhXZ0-0008Bd-5t; Fri, 14 May 2021 14:09:10 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1lhXYy-00042P-TJ; Fri, 14 May 2021 14:09:08 +0100 Date: Fri, 14 May 2021 14:09:08 +0100 From: "Russell King (Oracle)" To: Peter Geis Cc: Andrew Lunn , Heiner Kallweit , "David S . Miller" , Jakub Kicinski , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-rockchip@lists.infradead.org Subject: Re: [PATCH v3] net: phy: add driver for Motorcomm yt8511 phy Message-ID: <20210514130908.GD12395@shell.armlinux.org.uk> References: <20210514115826.3025223-1-pgwipeout@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210514115826.3025223-1-pgwipeout@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: Russell King (Oracle) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hi! On Fri, May 14, 2021 at 07:58:26AM -0400, Peter Geis wrote: > + /* set rgmii delay mode */ > + val = __phy_read(phydev, YT8511_PAGE); > + > + switch (phydev->interface) { > + case PHY_INTERFACE_MODE_RGMII: > + val &= ~(YT8511_DELAY_RX | YT8511_DELAY_TX); > + break; > + case PHY_INTERFACE_MODE_RGMII_ID: > + val |= YT8511_DELAY_RX | YT8511_DELAY_TX; > + break; > + case PHY_INTERFACE_MODE_RGMII_RXID: > + val &= ~(YT8511_DELAY_TX); > + val |= YT8511_DELAY_RX; > + break; > + case PHY_INTERFACE_MODE_RGMII_TXID: > + val &= ~(YT8511_DELAY_RX); > + val |= YT8511_DELAY_TX; > + break; > + default: /* leave everything alone in other modes */ > + break; > + } > + > + ret = __phy_write(phydev, YT8511_PAGE, val); > + if (ret < 0) > + goto err_restore_page; Another way of writing the above is to set "val" to be the value of the YT8511_DELAY_RX and YT8511_DELAY_TX bits, and then do: ret = __phy_modify(phydev, YT8511_PAGE, (YT8511_DELAY_RX | YT8511_DELAY_TX), val); if (ret < 0) goto err_restore_page; which moves the read-modify-write out of the driver into core code and makes the driver code smaller. It also handles your missing error check on __phy_read() above - would you want the above code to attempt to write a -ve error number back to this register? I suspect not! -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!