From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754171AbdFWDQq (ORCPT ); Thu, 22 Jun 2017 23:16:46 -0400 Received: from vps0.lunn.ch ([178.209.37.122]:60607 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753925AbdFWDQo (ORCPT ); Thu, 22 Jun 2017 23:16:44 -0400 Date: Fri, 23 Jun 2017 05:16:27 +0200 From: Andrew Lunn To: Lin Yun Sheng Cc: davem@davemloft.net, f.fainelli@gmail.com, huangdaode@hisilicon.com, xuwei5@hisilicon.com, liguozhu@hisilicon.com, Yisen.Zhuang@huawei.com, gabriele.paoloni@huawei.com, john.garry@huawei.com, linuxarm@huawei.com, salil.mehta@huawei.com, lipeng321@huawei.com, tremyfr@gmail.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH NET 1/2] net: phy: Add phy loopback support in net phy framework Message-ID: <20170623031627.GA5432@lunn.ch> References: <1498121602-64322-1-git-send-email-linyunsheng@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1498121602-64322-1-git-send-email-linyunsheng@huawei.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > +int genphy_loopback(struct phy_device *phydev, bool enable) > +{ > + int value; > + > + if (enable) { > + value = phy_read(phydev, MII_BMCR); > + phy_write(phydev, MII_BMCR, value | BMCR_LOOPBACK); > + } else { > + value = phy_read(phydev, MII_BMCR); > + phy_write(phydev, MII_BMCR, value & ~BMCR_LOOPBACK); > + } You should add error checking here. Both phy_read and phy_write can return an error. Also, do the read and write once. > + > + return 0; > +} > +EXPORT_SYMBOL(genphy_loopback); > + > +static int gen10g_loopback(struct phy_device *phydev, bool enable) > +{ > + return 0; > +} This is pointless. The core code in phy.c should first check if the function exists before calling it. So not having a 10g method is fine. Andrew