From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756928AbbFQSl7 (ORCPT ); Wed, 17 Jun 2015 14:41:59 -0400 Received: from mail-pd0-f173.google.com ([209.85.192.173]:35776 "EHLO mail-pd0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753644AbbFQSlx (ORCPT ); Wed, 17 Jun 2015 14:41:53 -0400 Date: Wed, 17 Jun 2015 11:41:44 -0700 From: Brian Norris To: Richard Weinberger Cc: dwmw2@infradead.org, maximlevitsky@gmail.com, linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 6/6] mtd: docg3: Don't do ERR_PTR(0) Message-ID: <20150617184144.GH4917@ld-irv-0074> References: <1433193054-26865-1-git-send-email-richard@nod.at> <1433193054-26865-7-git-send-email-richard@nod.at> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1433193054-26865-7-git-send-email-richard@nod.at> 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 On Mon, Jun 01, 2015 at 11:10:54PM +0200, Richard Weinberger wrote: > Don't return a obfuscated null pointer using ERR_PTR(0). > If the no device is found clearly return -ENODEV. > This makes the code more clear and matches the comment > of doc_probe_device(). > > Signed-off-by: Richard Weinberger > --- Have you tested this patch? > drivers/mtd/devices/docg3.c | 16 ++++++---------- > 1 file changed, 6 insertions(+), 10 deletions(-) > > diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c > index 5e67b4a..630e29a 100644 > --- a/drivers/mtd/devices/docg3.c > +++ b/drivers/mtd/devices/docg3.c > @@ -1902,7 +1902,7 @@ doc_probe_device(struct docg3_cascade *cascade, int floor, struct device *dev) > chip_id = doc_register_readw(docg3, DOC_CHIPID); > chip_id_inv = doc_register_readw(docg3, DOC_CHIPID_INV); > > - ret = 0; > + ret = -ENODEV; > if (chip_id != (u16)(~chip_id_inv)) { > goto nomem4; > } > @@ -2068,13 +2068,10 @@ static int __init docg3_probe(struct platform_device *pdev) > mtd = doc_probe_device(cascade, floor, dev); > if (IS_ERR(mtd)) { > ret = PTR_ERR(mtd); > - goto err_probe; > - } > - if (!mtd) { > - if (floor == 0) > - goto notfound; > - else > + if (ret == -ENODEV && floor == 0) I think you might have changed the logic when refactoring here. I think the right refactoring would be the following, no? if (ret == -ENODEV && floor != 0) continue; else goto err_probe; > continue; > + else > + goto err_probe; > } > cascade->floors[floor] = mtd; > ret = mtd_device_parse_register(mtd, part_probes, NULL, NULL, > @@ -2091,10 +2088,9 @@ static int __init docg3_probe(struct platform_device *pdev) > doc_dbg_register(cascade->floors[0]->priv); > return 0; > > -notfound: > - ret = -ENODEV; > - dev_info(dev, "No supported DiskOnChip found\n"); > err_probe: > + if (ret == -ENODEV) > + dev_info(dev, "No supported DiskOnChip found\n"); > free_bch(cascade->bch); > for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++) > if (cascade->floors[floor]) Brian