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=-3.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 F2E0FC04A6B for ; Wed, 8 May 2019 14:35:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BE582216C8 for ; Wed, 8 May 2019 14:35:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727813AbfEHOf6 (ORCPT ); Wed, 8 May 2019 10:35:58 -0400 Received: from metis.ext.pengutronix.de ([85.220.165.71]:32939 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727588AbfEHOf6 (ORCPT ); Wed, 8 May 2019 10:35:58 -0400 Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=bjornoya.blackshift.org) by metis.ext.pengutronix.de with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hONfm-0002Tp-46; Wed, 08 May 2019 16:35:54 +0200 Received: from [192.168.137.87] (nat079013.nat.FH-Koeln.DE [139.6.79.13]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mkl@blackshift.org", Issuer "StartCom Class 1 Client CA" (not verified)) (Authenticated sender: mkl@blackshift.org) by smtp.blackshift.org (Postfix) with ESMTPSA id 5F168409C1D; Wed, 8 May 2019 14:35:51 +0000 (UTC) To: Dan Murphy , wg@grandegger.com, davem@davemloft.net Cc: linux-can@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <20190319172651.10012-1-dmurphy@ti.com> From: Marc Kleine-Budde Openpgp: preference=signencrypt Autocrypt: addr=mkl@pengutronix.de; prefer-encrypt=mutual; keydata= mQINBFFVq30BEACtnSvtXHoeHJxG6nRULcvlkW6RuNwHKmrqoksispp43X8+nwqIFYgb8UaX zu8T6kZP2wEIpM9RjEL3jdBjZNCsjSS6x1qzpc2+2ivjdiJsqeaagIgvy2JWy7vUa4/PyGfx QyUeXOxdj59DvLwAx8I6hOgeHx2X/ntKAMUxwawYfPZpP3gwTNKc27dJWSomOLgp+gbmOmgc 6U5KwhAxPTEb3CsT5RicsC+uQQFumdl5I6XS+pbeXZndXwnj5t84M+HEj7RN6bUfV2WZO/AB Xt5+qFkC/AVUcj/dcHvZwQJlGeZxoi4veCoOT2MYqfR0ax1MmN+LVRvKm29oSyD4Ts/97cbs XsZDRxnEG3z/7Winiv0ZanclA7v7CQwrzsbpCv+oj+zokGuKasofzKdpywkjAfSE1zTyF+8K nxBAmzwEqeQ3iKqBc3AcCseqSPX53mPqmwvNVS2GqBpnOfY7Mxr1AEmxdEcRYbhG6Xdn+ACq Dq0Db3A++3PhMSaOu125uIAIwMXRJIzCXYSqXo8NIeo9tobk0C/9w3fUfMTrBDtSviLHqlp8 eQEP8+TDSmRP/CwmFHv36jd+XGmBHzW5I7qw0OORRwNFYBeEuiOIgxAfjjbLGHh9SRwEqXAL kw+WVTwh0MN1k7I9/CDVlGvc3yIKS0sA+wudYiselXzgLuP5cQARAQABtCZNYXJjIEtsZWlu ZS1CdWRkZSA8bWtsQHBlbmd1dHJvbml4LmRlPokCVAQTAQoAPgIbAwIeAQIXgAULCQgHAwUV 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v1aamg2nAppZ16z4nAnGU/47tWZ4P8blLVG8x4SWzz3D7MCy1FsQBTrWGLqWldPhkBAGp2VH xDOK4rLhuQWx3H5zd3kPXaIgvHI3EliWaQN+u2xmTQSJN75I/V47QsaPvkm4TVe3JlB7l1Fg OmSvYx31YC+3slh89ayjPWt8hFaTLnB9NaW9bLhs3E2ESF9Dei0FRXIt3qnFV/hnETsx3X4h KEnXxhSRDVeURP7V6P/z3+WIfddVKZk5ZLHi39fJpxvsg9YLSfStMJ/cJfiPXk1vKdoa+FjN 7nGAZyF6NHTNhsI7aHnvZMDavmAD3lK6CY+UBGtGQA3QhrUc2cedp1V53lXwor/D/D3Wo9wY iSXKOl4fFCh2Peo7qYmFUaDdyiCxvFm+YcIeMZ8wO5udzkjDtP4lWKAn4tUcdcwMOT5d0I3q WATP4wFI8QktNBqF3VY47HFwF9PtNuOZIqeAquKezywUc5KqKdqEWCPx9pfLxBAh3GW2Zfjp lP6A5upKs2ktDZOC2HZXP4IJ1GTk8hnfS4ade8s9FNcwu9m3JlxcGKLPq5DnIbPVQI1UUR4F QyAqTtIdSpeFYbvH8D7pO4lxLSz2ZyBMk+aKKs6GL5MqEci8OcFW Subject: Re: [PATCH v11 1/5] can: m_can: Create a m_can platform framework Message-ID: <8b53474d-9dbf-4b81-defd-1587e022990b@pengutronix.de> Date: Wed, 8 May 2019 16:35:46 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190319172651.10012-1-dmurphy@ti.com> Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="1r7rTP50MEDVwdj8E3He51a7N0s6cxNS3" X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --1r7rTP50MEDVwdj8E3He51a7N0s6cxNS3 Content-Type: multipart/mixed; boundary="E6g4mkyKo6xVnHLkhPyEKWZ1mgUQRAkAe"; protected-headers="v1" From: Marc Kleine-Budde To: Dan Murphy , wg@grandegger.com, davem@davemloft.net Cc: linux-can@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Message-ID: <8b53474d-9dbf-4b81-defd-1587e022990b@pengutronix.de> Subject: Re: [PATCH v11 1/5] can: m_can: Create a m_can platform framework References: <20190319172651.10012-1-dmurphy@ti.com> In-Reply-To: <20190319172651.10012-1-dmurphy@ti.com> --E6g4mkyKo6xVnHLkhPyEKWZ1mgUQRAkAe Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: quoted-printable On 3/19/19 6:26 PM, Dan Murphy wrote: > Create a m_can platform framework that peripheral > devices can register to and use common code and register sets. > The peripheral devices may provide read/write and configuration > support of the IP. >=20 > Acked-by: Wolfgang Grandegger > Signed-off-by: Dan Murphy [...] > -/* m_can private data structure */ > -struct m_can_priv { > - struct can_priv can; /* must be the first member */ > - struct napi_struct napi; > - struct net_device *dev; > - struct device *device; > - struct clk *hclk; > - struct clk *cclk; > - void __iomem *base; > - u32 irqstatus; > - int version; > - > - /* message ram configuration */ > - void __iomem *mram_base; > - struct mram_cfg mcfg[MRAM_CFG_NUM]; > -}; > +static u32 m_can_read(struct m_can_priv *priv, enum m_can_reg reg) > +{ > + if (priv->ops->read_reg) > + return priv->ops->read_reg(priv, reg); > + else > + return -EINVAL; > +} How do you plan to check the return value here? What's the difference between a register value of 0xffffffe9 and returning -EINVAL? > =20 > -static inline u32 m_can_read(const struct m_can_priv *priv, enum m_can= _reg reg) > +static int m_can_write(struct m_can_priv *priv, enum m_can_reg reg, u3= 2 val) > { > - return readl(priv->base + reg); > + if (priv->ops->write_reg) > + return priv->ops->write_reg(priv, reg, val); > + else > + return -EINVAL; > } I don't see anyone checking the return value. Better just dereference the pointer and the kernel will produce a nice backtrace. Same should be done for all read and write variants. Marc --=20 Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de | --E6g4mkyKo6xVnHLkhPyEKWZ1mgUQRAkAe-- --1r7rTP50MEDVwdj8E3He51a7N0s6cxNS3 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCgAdFiEEmvEkXzgOfc881GuFWsYho5HknSAFAlzS6UIACgkQWsYho5Hk nSCf8wgAmQ8w7vrPaGZeDrxDQfBebFsuHOnulVeEZZ7YnwRN3y7fCVBIByDYv0ye BNEn8YzfkVWWg/nbqt3zvrP+YORxBCX1tvzi6CMen1GxB2IbdIuuRKZyLDhR2fHn ejD9uMteJ74EfYPS/Yr2GyascWbq9rd4FgAM/8SBwI5QVtJEjkm4BYu9rT+B4PmO X1aHpaQ8kSSCF9uXY2fxpOEihc2eWA+kGTyIGEfMV+Ubyweqs9ehz9CECB7A1/xu 0HC5fkLLln791p+Gv4kWJHHjVwZIDrw99SXDqdgokYlckJCa2Fnxbl7sTqRa2Drk l1ZEEnWVBxlg8jpurCSLl2a1QdqZww== =3wV/ -----END PGP SIGNATURE----- --1r7rTP50MEDVwdj8E3He51a7N0s6cxNS3--