From mboxrd@z Thu Jan 1 00:00:00 1970 From: Viresh Kumar Subject: Re: CpuFreq Laptop Scaling broken? Date: Tue, 26 Aug 2014 10:04:26 +0530 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: linux-rt-users@vger.kernel.org, Thomas Gleixner , Steven Rostedt , "Rafael J. Wysocki" To: Harry van Haaren Return-path: Received: from mail-oi0-f46.google.com ([209.85.218.46]:64204 "EHLO mail-oi0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750731AbaHZEe1 (ORCPT ); Tue, 26 Aug 2014 00:34:27 -0400 Received: by mail-oi0-f46.google.com with SMTP id i138so10298245oig.19 for ; Mon, 25 Aug 2014 21:34:26 -0700 (PDT) In-Reply-To: Sender: linux-rt-users-owner@vger.kernel.org List-ID: On 25 August 2014 19:32, Harry van Haaren wrote: > On Mon, Aug 25, 2014 at 2:55 PM, Viresh Kumar wrote: >> You tried both these as root? Even 'sudo' may not work.. > Yes, the original output was all as root (not sudo, genuine root). > >> I haven't seen the rt code since sometime, what tag should I look at ? > I'm running 3.14.12-rt9-1-rt (as packaged for Arch here: > https://aur.archlinux.org/packages/linux-rt ) I don't have a clue of what's going wrong here.. But my guess would be that something is not working with locking, as that's one of the main difference between rt and non-rt kernels. Can you try to debug it with some prints? The functions of interest would be, drivers/cpufreq/cpufreq.c: - static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) - static ssize_t store_scaling_governor(struct cpufreq_policy *policy, const char *buf, size_t count) Try to add some prints there while returning errors and then try to change governor from userspace and things might get somewhat better then.. -- viresh