Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933252AbbG1KBZ (ORCPT ); Tue, 28 Jul 2015 06:01:25 -0400 Received: from mx2.suse.de ([195.135.220.15]:57950 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755697AbbG1JxO (ORCPT ); Tue, 28 Jul 2015 05:53:14 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, "Rafael J. Wysocki" , Shilpasri G Bhat , Jiri Slaby Subject: [PATCH 3.12 106/124] cpuidle / menu: Return (-1) if there are no suitable states Date: Tue, 28 Jul 2015 11:52:47 +0200 Message-Id: X-Mailer: git-send-email 2.4.6 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2311 Lines: 64 From: "Rafael J. Wysocki" 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 3836785a1bdcd6706c68ad46bf53adc0b057b310 upstream. If there is a PM QoS latency limit and all of the sufficiently shallow C-states are disabled, the cpuidle menu governor returns 0 which on some systems is CPUIDLE_DRIVER_STATE_START and shouldn't be returned if that C-state has been disabled. Fix the issue by modifying the menu governor to return (-1) in such situations. Signed-off-by: Rafael J. Wysocki [shilpab: Backport to 3.10.y - adjust context - add a check if 'next_state' is less than 0 in 'cpuidle_idle_call()', this ensures that we exit 'cpuidle_idle_call()' if governor->select() returns negative value] Signed-off-by: Shilpasri G Bhat Signed-off-by: Jiri Slaby --- drivers/cpuidle/cpuidle.c | 3 +++ drivers/cpuidle/governors/menu.c | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 22c07fb6ab78..ef44248a5c37 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -133,6 +133,9 @@ int cpuidle_idle_call(void) /* ask the governor for the next state */ next_state = cpuidle_curr_governor->select(drv, dev); + if (next_state < 0) + return -EBUSY; + if (need_resched()) { dev->last_residency = 0; /* give the governor an opportunity to reflect on the outcome */ diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index cf7f2f0e4ef5..027c484e1ec9 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -297,7 +297,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) data->needs_update = 0; } - data->last_state_idx = 0; + data->last_state_idx = CPUIDLE_DRIVER_STATE_START - 1; data->exit_us = 0; /* Special case when user has set very strict latency requirement */ -- 2.4.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/