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=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 F198FC3F2D1 for ; Tue, 3 Mar 2020 15:30:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C60CE20848 for ; Tue, 3 Mar 2020 15:30:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="RMtEwPuH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729894AbgCCPaV (ORCPT ); Tue, 3 Mar 2020 10:30:21 -0500 Received: from pandora.armlinux.org.uk ([78.32.30.218]:37380 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728330AbgCCPaV (ORCPT ); Tue, 3 Mar 2020 10:30:21 -0500 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=0AOalMujzfvOp/qBTNhEuZ9p7mv0TJBRJaYBnhdgVL8=; b=RMtEwPuH2+iWJTvoAX4mY/lFZ 9YDhKjgowtPy5FCyDZVxr3fG9EmZvKmeXhukYcsuJjB6nHC65Q6fb06rE1n0G1vK5bJd5RjQGn5vk TRbFi8WR75wwgFRk7dIT9OVfF3rkz9aRZsRZqeKPITiU1Bv8Z4I2PuCZtidUIsA0ex9DtihIST5Xd 9I2bV+nYl3dNLt7vmM9G56UITFYsv7wvjJNUnMDCY2LocPmX07Mo+hFtbn8tzYnh0N8FnnN+YxFZe qit5YNKnjIdM07bM1MgPx0DlqfcA0zxzY3A5h5ARkFXFfYX5Gmspebl0xUPeCUTZypMmegA1DQlho hE+1Ku2Xg==; Received: from shell.armlinux.org.uk ([2002:4e20:1eda:1:5054:ff:fe00:4ec]:55738) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1j99Us-0000Lj-R3; Tue, 03 Mar 2020 15:30:14 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1j99Ur-00060a-FJ; Tue, 03 Mar 2020 15:30:13 +0000 Date: Tue, 3 Mar 2020 15:30:13 +0000 From: Russell King - ARM Linux admin To: Antoine Tenart Cc: Andrew Lunn , Florian Fainelli , Heiner Kallweit , "David S. Miller" , netdev@vger.kernel.org Subject: Re: [PATCH net-next 2/3] net: phy: marvell10g: add energy detect power down tunable Message-ID: <20200303153013.GQ25745@shell.armlinux.org.uk> References: <20200303144259.GM25745@shell.armlinux.org.uk> <20200303150741.GC3179@kwain> <20200303151232.GO25745@shell.armlinux.org.uk> <20200303151958.GE3179@kwain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200303151958.GE3179@kwain> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, Mar 03, 2020 at 04:19:58PM +0100, Antoine Tenart wrote: > On Tue, Mar 03, 2020 at 03:12:32PM +0000, Russell King - ARM Linux admin wrote: > > On Tue, Mar 03, 2020 at 04:07:41PM +0100, Antoine Tenart wrote: > > > On Tue, Mar 03, 2020 at 02:44:02PM +0000, Russell King wrote: > > > > drivers/net/phy/marvell10g.c | 111 ++++++++++++++++++++++++++++++++++- > > > > > > > > +static int mv3310_maybe_reset(struct phy_device *phydev, u32 unit, bool reset) > > > > +{ > > > > + int retries, val, err; > > > > + > > > > + if (!reset) > > > > + return 0; > > > > > > You could also call mv3310_maybe_reset after testing the 'reset' > > > condition, that would make it easier to read the code. > > > > I'm not too convinced: > > > > diff --git a/drivers/net/phy/marvell10g.c b/drivers/net/phy/marvell10g.c > > index ef1ed9415d9f..3daf73e61dff 100644 > > --- a/drivers/net/phy/marvell10g.c > > +++ b/drivers/net/phy/marvell10g.c > > @@ -279,13 +279,10 @@ static int mv3310_power_up(struct phy_device *phydev) > > MV_V2_PORT_CTRL_PWRDOWN); > > } > > > > -static int mv3310_maybe_reset(struct phy_device *phydev, u32 unit, bool reset) > > +static int mv3310_reset(struct phy_device *phydev, u32 unit) > > { > > int retries, val, err; > > > > - if (!reset) > > - return 0; > > - > > err = phy_modify_mmd(phydev, MDIO_MMD_PCS, unit + MDIO_CTRL1, > > MDIO_CTRL1_RESET, MDIO_CTRL1_RESET); > > if (err < 0) > > @@ -684,10 +681,10 @@ static int mv3310_config_mdix(struct phy_device *phydev) > > > > err = phy_modify_mmd_changed(phydev, MDIO_MMD_PCS, MV_PCS_CSCR1, > > MV_PCS_CSCR1_MDIX_MASK, val); > > - if (err < 0) > > + if (err <= 0) > > return err; > > > > - return mv3310_maybe_reset(phydev, MV_PCS_BASE_T, err > 0); > > + return mv3310_reset(phydev, MV_PCS_BASE_T); > > } > > > > static int mv3310_config_aneg(struct phy_device *phydev) > > > > The change from: > > > > if (err < 0) > > > > to: > > > > if (err <= 0) > > > > could easily be mistaken as a bug, and someone may decide to try to > > "fix" that back to being the former instead. The way I have the code > > makes the intention explicit. > > Using a single line to test both the error and the 'return 0' > conditions, yes, I agree. Another solution would be to do something of > the like: > > phy_modify_mmd_changed() > if (err < 0) > return err; > > if (err) > mv3310_reset(); > > return 0; > > I find it more readable, but this kind of thing is also a matter of > personal taste. Well, it either becomes: err = phy_modify_mmd_changed(phydev, MDIO_MMD_PCS, MV_PCS_CSCR1, MV_PCS_CSCR1_MDIX_MASK, val); if (err < 0) return err; if (err > 0) return mv3310_reset(phydev, MV_PCS_BASE_T); return 0; or: err = phy_modify_mmd_changed(phydev, MDIO_MMD_PCS, MV_PCS_CSCR1, MV_PCS_CSCR1_MDIX_MASK, val); if (err > 0) err = mv3310_reset(phydev, MV_PCS_BASE_T); return err; In the former case, we have two success-exit paths - one via a successful mv3310_reset() and one by dropping through to the final return statement. The latter case looks a bit better, at least to me. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up