Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753247AbdFSS5u (ORCPT + 2 others); Mon, 19 Jun 2017 14:57:50 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:52591 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753830AbdFSSiA (ORCPT ); Mon, 19 Jun 2017 14:38:00 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: Arnd Bergmann , "Rafael J . Wysocki" , Willy Tarreau Subject: [PATCH 3.10 212/268] ACPI / power: Avoid maybe-uninitialized warning Date: Mon, 19 Jun 2017 20:31:51 +0200 Message-Id: <1497897167-14556-213-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1497897167-14556-1-git-send-email-w@1wt.eu> References: <1497897167-14556-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: From: Arnd Bergmann commit fe8c470ab87d90e4b5115902dd94eced7e3305c3 upstream. gcc -O2 cannot always prove that the loop in acpi_power_get_inferred_state() is enterered at least once, so it assumes that cur_state might not get initialized: drivers/acpi/power.c: In function 'acpi_power_get_inferred_state': drivers/acpi/power.c:222:9: error: 'cur_state' may be used uninitialized in this function [-Werror=maybe-uninitialized] This sets the variable to zero at the start of the loop, to ensure that there is well-defined behavior even for an empty list. This gets rid of the warning. The warning first showed up when the -Os flag got removed in a bug fix patch in linux-4.11-rc5. I would suggest merging this addon patch on top of that bug fix to avoid introducing a new warning in the stable kernels. Fixes: 61b79e16c68d (ACPI: Fix incompatibility with mcount-based function graph tracing) Signed-off-by: Arnd Bergmann Signed-off-by: Rafael J. Wysocki Signed-off-by: Willy Tarreau --- drivers/acpi/power.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c index 288bb27..9954200 100644 --- a/drivers/acpi/power.c +++ b/drivers/acpi/power.c @@ -211,6 +211,7 @@ static int acpi_power_get_list_state(struct list_head *list, int *state) return -EINVAL; /* The state of the list is 'on' IFF all resources are 'on'. */ + cur_state = 0; list_for_each_entry(entry, list, node) { struct acpi_power_resource *resource = entry->resource; acpi_handle handle = resource->device.handle; -- 2.8.0.rc2.1.gbe9624a