From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:42247 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751033AbbGQBej (ORCPT ); Thu, 16 Jul 2015 21:34:39 -0400 Subject: Patch "cpuidle / menu: Return (-1) if there are no suitable states" has been added to the 3.10-stable tree To: rafael.j.wysocki@intel.com, gregkh@linuxfoundation.org, shilpa.bhat@linux.vnet.ibm.com Cc: , From: Date: Thu, 16 Jul 2015 18:34:39 -0700 Message-ID: <143709687925182@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled cpuidle / menu: Return (-1) if there are no suitable states to the 3.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: cpuidle-menu-return-1-if-there-are-no-suitable-states.patch and it can be found in the queue-3.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 3836785a1bdcd6706c68ad46bf53adc0b057b310 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 1 May 2014 00:14:04 +0200 Subject: cpuidle / menu: Return (-1) if there are no suitable states From: "Rafael J. Wysocki" 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: Greg Kroah-Hartman --- drivers/cpuidle/cpuidle.c | 3 +++ drivers/cpuidle/governors/menu.c | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -135,6 +135,9 @@ 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 */ --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -269,7 +269,7 @@ static int menu_select(struct cpuidle_dr 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 */ Patches currently in stable-queue which might be from rafael.j.wysocki@intel.com are queue-3.10/cpuidle-menu-return-1-if-there-are-no-suitable-states.patch