From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:52069 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751768AbbFCF16 (ORCPT ); Wed, 3 Jun 2015 01:27:58 -0400 Subject: Patch "thermal: step_wise: Revert optimization" has been added to the 3.14-stable tree To: jdelvare@suse.de, bpetkov@suse.de, eduardo.valentin@ti.com, peter@piie.net, rui.zhang@intel.com, shawn.guo@linaro.org, stable@vger.kernel.org Cc: , From: Date: Wed, 03 Jun 2015 14:27:52 +0900 In-Reply-To: <1429521673.4305.12.camel@chaos.site> Message-ID: <143330927210749@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 thermal: step_wise: Revert optimization to the 3.14-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: thermal-step_wise-revert-optimization.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From jdelvare@suse.de Wed Jun 3 14:21:51 2015 From: Jean Delvare Date: Mon, 20 Apr 2015 11:21:13 +0200 Subject: thermal: step_wise: Revert optimization To: stable Cc: Shawn Guo , Eduardo Valentin , Zhang Rui , Borislav Petkov Message-ID: <1429521673.4305.12.camel@chaos.site> From: Jean Delvare Commit 178c2490b99f898efc06d1ad75cadc84f13021a6 ("thermal: step_wise: cdev only needs update on a new target state") broke driver acerhdf. That driver abused the step_wise thermal governor until the bang_bang governor was available, and the optimization broke this usage model. Kernels v3.12 to v3.18 are affected. In v3.19 the acerhdf driver was switched to the bang_bang governor and that solved the problem. For kernels v3.12 to v3.17, the bang_bang governor isn't available yet so the easiest fix is to revert the optimization. Signed-off-by: Jean Delvare Reported-by: Dieter Jurzitza (https://bugzilla.opensuse.org/show_bug.cgi?id=925961) Tested-by: Peter Feuerer Tested-by: Dieter Jurzitza --- Please consider this patch for stable kernel branches from v3.12 to v3.17. If anyone cares about v3.18, I think a better fix would be to backport commit 48c8dd64345ba2a8c41556095c7adacb1c8af7c1 ("acerhdf: Use bang-bang thermal governor") but it's too big for stable, so it's left to distributions. So maybe this fix should make it into v3.18 stable as well - I'll let whoever maintains that branch decide. drivers/thermal/step_wise.c | 3 --- 1 file changed, 3 deletions(-) --- a/drivers/thermal/step_wise.c +++ b/drivers/thermal/step_wise.c @@ -146,9 +146,6 @@ static void thermal_zone_trip_update(str dev_dbg(&instance->cdev->device, "old_target=%d, target=%d\n", old_target, (int)instance->target); - if (old_target == instance->target) - continue; - /* Activate a passive thermal instance */ if (old_target == THERMAL_NO_TARGET && instance->target != THERMAL_NO_TARGET) Patches currently in stable-queue which might be from jdelvare@suse.de are queue-3.14/thermal-step_wise-revert-optimization.patch queue-3.14/hwmon-nct6775-add-missing-sysfs-attribute-initialization.patch