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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 81349C433EF for ; Sat, 6 Nov 2021 20:27:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 62299608FB for ; Sat, 6 Nov 2021 20:27:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235046AbhKFU3l (ORCPT ); Sat, 6 Nov 2021 16:29:41 -0400 Received: from mxout02.lancloud.ru ([45.84.86.82]:42480 "EHLO mxout02.lancloud.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233034AbhKFU3k (ORCPT ); Sat, 6 Nov 2021 16:29:40 -0400 Received: from LanCloud DKIM-Filter: OpenDKIM Filter v2.11.0 mxout02.lancloud.ru 738622293339 Received: from LanCloud Received: from LanCloud Received: from LanCloud To: Greg Kroah-Hartman , "Rafael J. Wysocki" CC: From: Sergey Shtylyov Subject: [PATCH] platform: finally disallow IRQ0 in platform_get_irq() and its ilk Organization: Open Mobile Platform Message-ID: <5e001ec1-d3f1-bcb8-7f30-a6301fd9930c@omp.ru> Date: Sat, 6 Nov 2021 23:26:47 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.11.198] X-ClientProxiedBy: LFEXT02.lancloud.ru (fd00:f066::142) To LFEX1907.lancloud.ru (fd00:f066::207) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The commit a85a6c86c25b ("driver core: platform: Clarify that IRQ 0 is invalid") only calls WARN() when IRQ0 is about to be returned, however using IRQ0 is considered invalid (according to Linus) outside the arch/ code where it's used by the i8253 drivers. Many driver subsystems treat 0 specially (e.g. as an indication of the polling mode by libata), so the users of platform_get_irq[_byname]() in them would have to filter out IRQ0 explicitly and this (quite obviously) doesn't scale... Let's finally get this straight and return -EINVAL instead of IRQ0! Fixes: a85a6c86c25b ("driver core: platform: Clarify that IRQ 0 is invalid") Signed-off-by: Sergey Shtylyov --- The patch is against the 'driver-core-linus' branch of Greg Kroah-Hartman's 'driver-core.git' repo. drivers/base/platform.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) Index: driver-core/drivers/base/platform.c =================================================================== --- driver-core.orig/drivers/base/platform.c +++ driver-core/drivers/base/platform.c @@ -231,7 +231,8 @@ int platform_get_irq_optional(struct pla out_not_found: ret = -ENXIO; out: - WARN(ret == 0, "0 is an invalid IRQ number\n"); + if (WARN(!ret, "0 is an invalid IRQ number\n")) + return -EINVAL; return ret; } EXPORT_SYMBOL_GPL(platform_get_irq_optional); @@ -445,7 +446,8 @@ static int __platform_get_irq_byname(str r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name); if (r) { - WARN(r->start == 0, "0 is an invalid IRQ number\n"); + if (WARN(!r->start, "0 is an invalid IRQ number\n")) + return -EINVAL; return r->start; }