From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Rothwell Subject: Re: linux-next: build warning after merge of the drivers-x86 tree Date: Thu, 15 Dec 2016 11:02:19 +1100 Message-ID: <20161215110219.61fec1a0@canb.auug.org.au> References: <20161214135044.57dc96f5@canb.auug.org.au> <20161214222138.GA116314@f23x64.localdomain> <20161214225914.GA7743@f23x64.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20161214225914.GA7743@f23x64.localdomain> Sender: linux-kernel-owner@vger.kernel.org To: Darren Hart Cc: linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, Lyude , Henrique de Moraes Holschuh , Andy Shevchenko List-Id: linux-next.vger.kernel.org Hi Darren, On Wed, 14 Dec 2016 14:59:14 -0800 Darren Hart wrote: > > 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: > > > > > > 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. How about "type". > 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. No problem, it is only a warning after all. -- Cheers, Stephen Rothwell