From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934110AbcLNW7V (ORCPT ); Wed, 14 Dec 2016 17:59:21 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:49602 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933070AbcLNW7U (ORCPT ); Wed, 14 Dec 2016 17:59:20 -0500 Date: Wed, 14 Dec 2016 14:59:14 -0800 From: Darren Hart To: Stephen Rothwell Cc: linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, Lyude , Henrique de Moraes Holschuh , Andy Shevchenko Subject: Re: linux-next: build warning after merge of the drivers-x86 tree Message-ID: <20161214225914.GA7743@f23x64.localdomain> References: <20161214135044.57dc96f5@canb.auug.org.au> <20161214222138.GA116314@f23x64.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161214222138.GA116314@f23x64.localdomain> User-Agent: Mutt/1.7.1 (2016-10-04) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 14, 2016 at 02:21:38PM -0800, Darren Hart wrote: > On Wed, Dec 14, 2016 at 01:50:44PM +1100, Stephen Rothwell wrote: > > Hi Darren, > > > > After merging the drivers-x86 tree, today's linux-next build (x86_64 > > allmodconfig) produced this warning: > > > > In file included from include/linux/kernel.h:13:0, > > from drivers/platform/x86/thinkpad_acpi.c:52: > > drivers/platform/x86/thinkpad_acpi.c: In function 'hotkey_init': > > include/linux/printk.h:299:2: warning: 'type' may be used uninitialized in this function [-Wmaybe-uninitialized] > > printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__) > > ^ > > drivers/platform/x86/thinkpad_acpi.c:3147:8: note: 'type' was declared here > > char *type; > > ^ > > In file included from include/linux/kernel.h:13:0, > > from drivers/platform/x86/thinkpad_acpi.c:52: > > include/linux/printk.h:299:2: warning: 'in_tablet_mode' may be used uninitialized in this function [-Wmaybe-uninitialized] > > printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__) > > ^ > > drivers/platform/x86/thinkpad_acpi.c:3146:6: note: 'in_tablet_mode' was declared here > > int in_tablet_mode, res; > > ^ > > > > Introduced by commit > > > > b31800283868 ("platform/x86: thinkpad_acpi: Move tablet detection into separate function") > > > > I can't tell if this is a false positive or not. > > That's an uninitialized local variable. Not sure how I missed that. I'll > fix it up today. Thank you for the report. OK, no, it's a false positive because tp_features.hotkey_tablet is assigned in both places where in_tablet_mode is assigned, and if the former is 0 (global scope), the function returns without calling pr_info. Lyude, Henrique, please confirm. Regardless, I'll add a patch to init in_tablet_mode to 0 so it is explicit - but will not rebase as it isn't technically an error. -- Darren Hart Intel Open Source Technology Center