From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Herkt Subject: ASUS PU551LD, fan stuck at full speed after waking up from S3 Date: Fri, 29 May 2015 13:51:57 +0200 Message-ID: <1949840.6Csghk90X0@sakuya> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7Bit Return-path: Received: from srsfckn.biz ([148.251.137.227]:37819 "EHLO srsfckn.biz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753035AbbE2L6d (ORCPT ); Fri, 29 May 2015 07:58:33 -0400 Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org Cc: linux-acpi@vger.kernel.org, platform-driver-x86@vger.kernel.org, acpi4asus-user@lists.sourceforge.net, linux-pm@vger.kernel.org My ASUS PU551LD laptop has a problem with its fan state when resuming from S3. In particular, the fan goes to full speed a second or two after waking up and cannot be reset without turning off the laptop. For example, rebooting to Windows and doing a suspend/resume cycle while the fan is in bad state will not reset it. I have observed this behavior with all kernel versions I have used on this laptop (oldest being 3.16, newest 4.1-rc5). sensors(1) does not show any fans, but asus-nb-wmi exposes /sys/class/hwmon/hwmon2/pwm1, which shows values like 85 during normal operation but goes to the expected 255 when the fan is running at full speed after waking up from S3. acpidump output: https://0x0.st/9Z.out Not being a kernel dev (but knowing C), what can I do to help fix this issue?