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=-9.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 5FD83C388F7 for ; Fri, 13 Nov 2020 07:10:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DE9A020B80 for ; Fri, 13 Nov 2020 07:10:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="1j/xvyLt"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="hroMx/wL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726325AbgKMHKz (ORCPT ); Fri, 13 Nov 2020 02:10:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45918 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726083AbgKMHKy (ORCPT ); Fri, 13 Nov 2020 02:10:54 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 827BFC0613D1; Thu, 12 Nov 2020 23:10:54 -0800 (PST) From: Kurt Kanzenbach DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1605251452; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=p661EQmTuzLYneEuJa/ev2/JCDeTtK3+51IrCpEGIx4=; b=1j/xvyLtnRgZWBKfjeCcMAOE9yhTELeF2yKA2/BrSin3vL6x31DcOMwKBmZke2LNTnU38B BEtI0/z4/zCSrc1HACJW4pPgYsQ4X7ILKM1LL5OivmjhdQE8eCoNIPpcIUPGCvIEWMK1Fb z6+NlWGqB01O0Est5Iw1bHZ++Nj3+8LuEgKC19aj+5ITpYMf1+K/5oGxgJLY67GiUQ4+Wx IgPZqxi8eRZFTHLYSxZcyqDvF4FiUH4/Fh4lWPfoSZHIDADy6RMYY0nY1at2GA5BGzX00G x/WqPQTKNAe+oW5Gy1GYeskq4exxfbd40tP3rZvbdwHSic9PhjD9A0MZX9mCBw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1605251452; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=p661EQmTuzLYneEuJa/ev2/JCDeTtK3+51IrCpEGIx4=; b=hroMx/wLMdj6QQiA8kbT3d6n6Py4NG0TqJBy2Jo8wL188cAPX0eqUw3AbrFJDo+WKgirA5 djrsuOYQ9R26hNCw== To: YueHaibing , olteanv@gmail.com, andrew@lunn.ch, vivien.didelot@gmail.com, f.fainelli@gmail.com, davem@davemloft.net, kuba@kernel.org Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, YueHaibing , Richard Cochran Subject: Re: [PATCH] net: dsa: sja1105: Fix return value check in sja1105_ptp_clock_register() In-Reply-To: <20201112145532.38320-1-yuehaibing@huawei.com> References: <20201112145532.38320-1-yuehaibing@huawei.com> Date: Fri, 13 Nov 2020 08:10:42 +0100 Message-ID: <87a6vlspe5.fsf@kurt> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha512; protocol="application/pgp-signature" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Thu Nov 12 2020, YueHaibing wrote: > drivers/net/dsa/sja1105/sja1105_ptp.c:869 sja1105_ptp_clock_register() wa= rn: passing zero to 'PTR_ERR' > > ptp_clock_register() returns ERR_PTR() and never returns > NULL. The NULL test should be removed. Which is not true. From the documentation: * Returns a valid pointer on success or PTR_ERR on failure. If PHC * support is missing at the configuration level, this function * returns NULL, and drivers are expected to gracefully handle that * case separately. Please, always Cc Richard for PTP patches. Actually you can have a look at this discussion here: https://lkml.kernel.org/netdev/1605086686-5140-1-git-send-email-wangqing@v= ivo.com/ > > Fixes: bb77f36ac21d ("net: dsa: sja1105: Add support for the PTP clock") > Signed-off-by: YueHaibing > --- > drivers/net/dsa/sja1105/sja1105_ptp.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/dsa/sja1105/sja1105_ptp.c b/drivers/net/dsa/sja1= 105/sja1105_ptp.c > index 1b90570b257b..1e41d491c854 100644 > --- a/drivers/net/dsa/sja1105/sja1105_ptp.c > +++ b/drivers/net/dsa/sja1105/sja1105_ptp.c > @@ -865,7 +865,7 @@ int sja1105_ptp_clock_register(struct dsa_switch *ds) > spin_lock_init(&tagger_data->meta_lock); >=20=20 > ptp_data->clock =3D ptp_clock_register(&ptp_data->caps, ds->dev); > - if (IS_ERR_OR_NULL(ptp_data->clock)) > + if (IS_ERR(ptp_data->clock)) When you do this, you'll have to make sure that the driver handles the NULL case "gracefully". 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