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 64EE7C433FE for ; Tue, 26 Apr 2022 10:48:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349388AbiDZKvH (ORCPT ); Tue, 26 Apr 2022 06:51:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36686 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349344AbiDZKuc (ORCPT ); Tue, 26 Apr 2022 06:50:32 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB8A254F9B for ; Tue, 26 Apr 2022 03:46:56 -0700 (PDT) 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 ams.source.kernel.org (Postfix) with ESMTPS id 2E4FCB81D2C for ; Tue, 26 Apr 2022 10:46:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 25117C385A0; Tue, 26 Apr 2022 10:46:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1650970013; bh=ebY/+/pigrgRUdbBV6C1hDE8PF2Rwpv8OgEzY37reaU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Ux0FdlSlaru2e2HzG3SQut49DRnwze94TQveHAt+Q9g7d3wB43RtDkULcmA/4yWOT Zi+0/xCKR4yopjIYqkPHl7jkJTHVYhXHQEMAJksmCKOn7W71ARkM+TA98aSMbw2pT4 lG92e4aTmcx0F0r/jcp9RW/UGKa+wfi54hyXBAmc= Date: Tue, 26 Apr 2022 12:46:35 +0200 From: Greg Kroah-Hartman To: Sergey Shtylyov Cc: "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, Marc Zyngier Subject: Re: [PATCH v2] platform: finally disallow IRQ0 in platform_get_irq() and its ilk Message-ID: References: <025679e1-1f0a-ae4b-4369-01164f691511@omp.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <025679e1-1f0a-ae4b-4369-01164f691511@omp.ru> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 11, 2022 at 10:35:29PM +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 > Acked-by: Marc Zyngier > > --- > The patch is against the 'driver-core-next' branch of Greg Kroah-Hartman's > 'driver-core.git' repo. > > Changes in version 2: > - added Marc's ACK. > > 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); > @@ -446,7 +447,8 @@ 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; > } > Ok, let's try this now. Worst case, we revert it later :) thanks, greg k-h