From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ryan Underwood Subject: transition latency Date: Thu, 28 Sep 2006 19:32:47 -0500 Message-ID: <20060929003247.GA20765@dbz.icequake.net> Reply-To: nemesis@icequake.net Mime-Version: 1.0 Return-path: Content-Disposition: inline List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: cpufreq-bounces@lists.linux.org.uk Errors-To: cpufreq-bounces+glkc-cpufreq=m.gmane.org+glkc-cpufreq=m.gmane.org@lists.linux.org.uk Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: cpufreq@lists.linux.org.uk What's the purpose of the transition_latency field with respect to the cpufreq infrastructure? Should I be setting this to: * the time it takes for my set_cpu_state function to execute and return * the latency between the call to set_cpu_state and the actual CPU speed change * the time it takes for the hardware to respond to MY request (inside set_cpu_state function) to change speeds Just a little confused. Here the problem is that my set_cpu_state function could take up to 35ms to execute, but the actual frequency transition ( a component of that function) happens within 7ms. 10ms is the ondemand/conservative governors' upper limit for transition latency, so if I take the whole function into account, those governors reject my driver. -- Ryan Underwood,