From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 34FF5134A8 for ; Thu, 7 Sep 2023 16:20:02 +0000 (UTC) Received: from pandora.armlinux.org.uk (unknown [IPv6:2001:4d48:ad52:32c8:5054:ff:fe00:142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D487493CB; Thu, 7 Sep 2023 09:19:38 -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=F7vSpfCfYCvODMAyXRt6Ug4ZFfLol/1tefnPrblJooA=; b=fMOtER0Kc3s0dWOOXdWUtzuoWA dWl8L35t9P5Oddj5gWtY8xsnKWUvCkbc/D1Ac/S/bGTbqaQBUZeF225T2faMESNfQYx+alM5b26cp 2Zd6OJJ660Y9ofKMEWwcBhxl29S77LF5hhkur4SX1RKv25PGVCNnh92l4JzJ+xVRAnd680jY5Ojwj x8pg96Xg6igE69LQ0fWlmaiomAI+vapPlLtSf3cgAUY4xvbC62dX13Cdl4Nyrgvagtc7KUxUDIPTV vzWxJTxfivuKIOOvk8UfxrknCPUVQz8sZmTH29NDO7EyhS7oU8WYc9CGZoEZfAqfDq0tCIAlpFmM/ qMfs6kww==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:48762) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1qeAWl-0001ci-0Q; Thu, 07 Sep 2023 09:38:15 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1qeAWd-0005ft-Ce; Thu, 07 Sep 2023 09:38:07 +0100 Date: Thu, 7 Sep 2023 09:38:07 +0100 From: "Russell King (Oracle)" To: Bo Liu Cc: iyappan@os.amperecomputing.com, keyur@os.amperecomputing.com, quan@os.amperecomputing.com, andrew@lunn.ch, hkallweit1@gmail.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] net: mdio: Use helper function IS_ERR_OR_NULL() Message-ID: References: <20230907071705.3907-1-liubo03@inspur.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230907071705.3907-1-liubo03@inspur.com> Sender: Russell King (Oracle) X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_BLOCKED,RDNS_NONE, SPF_HELO_NONE,SPF_NONE autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On Thu, Sep 07, 2023 at 03:17:05AM -0400, Bo Liu wrote: > Use IS_ERR_OR_NULL() to detect an error pointer or a null pointer > open-coding to simplify the code. > > Signed-off-by: Bo Liu Please do a more thorough review of the code before proposing changes to discover what the correct solution should be. > diff --git a/drivers/net/mdio/mdio-xgene.c b/drivers/net/mdio/mdio-xgene.c > index 1190a793555a..1518abfc3e22 100644 > --- a/drivers/net/mdio/mdio-xgene.c > +++ b/drivers/net/mdio/mdio-xgene.c > @@ -263,7 +263,7 @@ struct phy_device *xgene_enet_phy_register(struct mii_bus *bus, int phy_addr) > struct phy_device *phy_dev; > > phy_dev = get_phy_device(bus, phy_addr, false); > - if (!phy_dev || IS_ERR(phy_dev)) > + if (IS_ERR_OR_NULL(phy_dev)) Looking at get_phy_device(), the returns from this function are either: if (r) return ERR_PTR(r); which can't return NULL, or the return value from phy_device_create(). Looking at phy_device_create(), the returns from this function are: if (!dev) return ERR_PTR(-ENOMEM); if (ret) { ... dev = ERR_PTR(ret); ... return dev; so I don't see any of this being able to return NULL either. Therefore, the code that you are modifying should be: - if (!phy_dev || IS_ERR(phy_dev)) + if (IS_ERR(phy_dev)) and the commit description needs to be updated to state that get_phy_device() does not return NULL. Thanks. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!