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 5DEC5C433EF for ; Fri, 10 Dec 2021 11:37:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240696AbhLJLlW (ORCPT ); Fri, 10 Dec 2021 06:41:22 -0500 Received: from mga02.intel.com ([134.134.136.20]:28254 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240626AbhLJLlV (ORCPT ); Fri, 10 Dec 2021 06:41:21 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10193"; a="225603944" X-IronPort-AV: E=Sophos;i="5.88,195,1635231600"; d="scan'208";a="225603944" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Dec 2021 03:37:39 -0800 X-IronPort-AV: E=Sophos;i="5.88,195,1635231600"; d="scan'208";a="543952620" Received: from smile.fi.intel.com ([10.237.72.184]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Dec 2021 03:37:37 -0800 Received: from andy by smile.fi.intel.com with local (Exim 4.95) (envelope-from ) id 1mveCd-004TN5-3z; Fri, 10 Dec 2021 13:36:39 +0200 Date: Fri, 10 Dec 2021 13:36:38 +0200 From: Andy Shevchenko To: Sergey Shtylyov Cc: Damien Le Moal , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, Hans de Goede , Jens Axboe Subject: Re: [PATCH v1 1/2] ata: libahci_platform: Get rid of dup message when IRQ can't be retrieved Message-ID: References: <20211209145937.77719-1-andriy.shevchenko@linux.intel.com> <9e6b2e9a-e958-0c14-6570-135607041978@omp.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9e6b2e9a-e958-0c14-6570-135607041978@omp.ru> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: linux-ide@vger.kernel.org On Fri, Dec 10, 2021 at 02:19:52PM +0300, Sergey Shtylyov wrote: > On 12/10/21 1:46 PM, Andy Shevchenko wrote: > > >>>> platform_get_irq() will print a message when it fails. > >>>> No need to repeat this. > >>>> > >>>> While at it, drop redundant check for 0 as platform_get_irq() spills > >>>> out a big WARN() in such case. > >>> > >>> The reason you should be able to remove the "if (!irq)" test is that > >>> platform_get_irq() never returns 0. At least, that is what the function kdoc > >>> says. But looking at platform_get_irq_optional(), which is called by > >>> platform_get_irq(), the out label is: > >>> > >>> WARN(ret == 0, "0 is an invalid IRQ number\n"); > >>> return ret; > >>> > >>> So 0 will be returned as-is. That is rather weird. That should be fixed to > >>> return -ENXIO: > >>> > >>> if (WARN(ret == 0, "0 is an invalid IRQ number\n")) > >>> return -ENXIO; > >>> return ret; > >> > >> My unmerged patch (https://marc.info/?l=linux-kernel&m=163623041902285) does this > >> but returns -EINVAL instead. > >> > >>> Otherwise, I do not think that removing the "if (!irq)" hunk is safe. no ? > >> > >> Of course it isn't... > > > > It's unsubstantiated statement. The vIRQ 0 shouldn't be returned by any of > > those API calls. > > We do _not_ know what needs to be fixed, that's the problem, and that's why the WARN() > is there... So, have you seen this warning (being reported) related to libahci_platform? If no, what we are discussing about then? The workaround is redundant and no need to have a dead code in the driver, really. > > If it is the case, go and fix them, no need to workaround > > in each of the callers. > > There's a need to work around as long as IRQ0 ican be returned, otherwise > we get partly functioning or non-functioning drivers... You get them unfunctioning anyways and you get the big WARN() even before this patch. -- With Best Regards, Andy Shevchenko