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=-6.5 required=3.0 tests=FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 EC0D9C433E0 for ; Wed, 27 May 2020 18:26:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DA69B20899 for ; Wed, 27 May 2020 18:26:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389304AbgE0S0l (ORCPT ); Wed, 27 May 2020 14:26:41 -0400 Received: from smtp06.smtpout.orange.fr ([80.12.242.128]:20290 "EHLO smtp.smtpout.orange.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388887AbgE0S0l (ORCPT ); Wed, 27 May 2020 14:26:41 -0400 Received: from belgarion ([86.210.245.36]) by mwinf5d11 with ME id juSb220020nqnCN03uSbp8; Wed, 27 May 2020 20:26:39 +0200 X-ME-Helo: belgarion X-ME-Auth: amFyem1pay5yb2JlcnRAb3JhbmdlLmZy X-ME-Date: Wed, 27 May 2020 20:26:39 +0200 X-ME-IP: 86.210.245.36 From: Robert Jarzmik To: Tiezhu Yang Cc: Linus Walleij , Bartosz Golaszewski , Ray Jui , bcm-kernel-feedback-list@broadcom.com, linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, Xuefeng Li Subject: Re: [PATCH 2/3] gpio: pxa: Fix return value of pxa_gpio_probe() References: <1590120740-22912-1-git-send-email-yangtiezhu@loongson.cn> <1590120740-22912-2-git-send-email-yangtiezhu@loongson.cn> <874ks7okk4.fsf@belgarion.home> <3382c1df-1429-ecd3-70b6-35bc00343608@loongson.cn> X-URL: http://belgarath.falguerolles.org/ Date: Wed, 27 May 2020 20:26:07 +0200 In-Reply-To: <3382c1df-1429-ecd3-70b6-35bc00343608@loongson.cn> (Tiezhu Yang's message of "Sat, 23 May 2020 11:24:46 +0800") Message-ID: <87zh9tmdz4.fsf@belgarion.home> User-Agent: Gnus/5.130008 (Ma Gnus v0.8) Emacs/26 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Tiezhu Yang writes: > On 05/23/2020 03:07 AM, Robert Jarzmik wrote: >> Tiezhu Yang writes: >> >>> When call function devm_platform_ioremap_resource(), we should use IS_ERR() >>> to check the return value and return PTR_ERR() if failed. >>> >>> Fixes: 542c25b7a209 ("drivers: gpio: pxa: use devm_platform_ioremap_resource()") >>> Signed-off-by: Tiezhu Yang >>> --- >>> drivers/gpio/gpio-pxa.c | 4 ++-- >>> 1 file changed, 2 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/gpio/gpio-pxa.c b/drivers/gpio/gpio-pxa.c >>> index 1361270..0cb6600 100644 >>> --- a/drivers/gpio/gpio-pxa.c >>> +++ b/drivers/gpio/gpio-pxa.c >>> @@ -660,8 +660,8 @@ static int pxa_gpio_probe(struct platform_device *pdev) >>> pchip->irq1 = irq1; >>> gpio_reg_base = devm_platform_ioremap_resource(pdev, 0); >>> - if (!gpio_reg_base) >>> - return -EINVAL; >>> + if (IS_ERR(gpio_reg_base)) >>> + return PTR_ERR(gpio_reg_base); >> As far as I know, devm_platform_ioremap_resource() could return NULL which is >> not handled by this test (unless __devm_ioremap() semantics changed since I had >> a look). > > Hi Robert, > > In the function __devm_ioremap_resource(), if __devm_ioremap returns NULL, > it will return IOMEM_ERR_PTR(-ENOMEM). > > devm_platform_ioremap_resource() > devm_ioremap_resource() > __devm_ioremap_resource() > __devm_ioremap() > > static void __iomem * > __devm_ioremap_resource(struct device *dev, const struct resource *res, > enum devm_ioremap_type type) > { > ... > dest_ptr = __devm_ioremap(dev, res->start, size, type); > if (!dest_ptr) { > dev_err(dev, "ioremap failed for resource %pR\n", res); > devm_release_mem_region(dev, res->start, size); > dest_ptr = IOMEM_ERR_PTR(-ENOMEM); > } > > return dest_ptr; > } > > And also, we can see the comment of devm_ioremap_resource(): > > Usage example: > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > base = devm_ioremap_resource(&pdev->dev, res); > if (IS_ERR(base)) > return PTR_ERR(base); > >> >> Therefore, this patch is incorrect, or rather incomplete. > > So I think this patch is correct, do I miss something? You're right, my bad, didn't see the test in __devm_ioremap_resource(). Cheers. -- Robert