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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 96402C433F5 for ; Fri, 26 Nov 2021 16:22:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239510AbhKZQZw (ORCPT ); Fri, 26 Nov 2021 11:25:52 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:37500 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231174AbhKZQXu (ORCPT ); Fri, 26 Nov 2021 11:23:50 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 95DE9622DE for ; Fri, 26 Nov 2021 16:20:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 68770C93056; Fri, 26 Nov 2021 16:20:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1637943637; bh=hHzRt7omLgTYdRrbsO+/umgidnNO13xR556zj8JayD0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OU7kIkqGCRQBVPSI8iC61SEzs/vzOLWDmnGz10io8BXjvDU9j+zY5r3vswzII2Kxx LTCO1RYfvy38jA4a9Cp9AoYfhiT9DAAErpUYq7wRz6KgZ1PsBOuGCkz0vebzthKBdJ TblfX41vmjawq79ENmCy+7uDI9eune4sK1upJjzo= Date: Fri, 26 Nov 2021 17:20:34 +0100 From: Greg Kroah-Hartman To: Sergey Shtylyov Cc: "Rafael J. Wysocki" , linux-kernel@vger.kernel.org Subject: Re: [PATCH] platform: finally disallow IRQ0 in platform_get_irq() and its ilk Message-ID: References: <5e001ec1-d3f1-bcb8-7f30-a6301fd9930c@omp.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5e001ec1-d3f1-bcb8-7f30-a6301fd9930c@omp.ru> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Nov 06, 2021 at 11:26:47PM +0300, Sergey Shtylyov wrote: > 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; You need to get approval from the interrrupt developers for this type of change, as it is a change and might break existing platforms, right? thanks, greg k-h