From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dominik Brodowski Subject: Re: ACPI P-State platform limit [Was: Re: Cpufreq for opteron] Date: Fri, 5 Sep 2003 00:29:04 +0200 Sender: cpufreq-bounces+glkc-cpufreq=gmane.org@www.linux.org.uk Message-ID: <20030904222904.GA6488@brodo.de> References: <99F2150714F93F448942F9A9F112634C080EF034@txexmtae.amd.com> <20030827053300.GB4037@brodo.de> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <20030827053300.GB4037@brodo.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: cpufreq-bounces+glkc-cpufreq=gmane.org@www.linux.org.uk Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: paul.devriendt@AMD.com Cc: pavel@suse.cz, richard.brunner@AMD.com, aj@suse.de, cpufreq@www.linux.org.uk, davej@redhat.com, mark.langsdorf@AMD.com On Wed, Aug 27, 2003 at 07:33:00AM +0200, Dominik Brodowski wrote: > [removed CC:linux-kernel] > > > > I dislike this interaction between ACPI and cpufreq -- it > > > should be done > > > more generally. Let's discuss that seperately, though. And if > > > the code is > > > dead code at the moment. > > > > The dead code has been removed in 1.00.07 of the driver. I am > > happy to receive suggestions as to better ways of detecting battery > > versus mains power transitions. > > Currently, the ACPI P-States cpufreq driver does implement the "platform > limit". However, I'm not really excited about how it works -- and especially > that it only works with the ACPI P-States cpufreq driver and not with all > drivers. > > The platform limit [ _PPC ] refers to the states defined in _PSS. This means > that this knowledge can and should be used independent of the cpufreq driver: > if the _PPC is, let's say, 2, and accoring to _PSS P2 is 1.2 GHz, a > "platform limit CPUFREQ_POLICY_NOTIFIER". If the _PPC changes, a > new cpufreq_reevaluate() function should be called: I named it cpufreq_update_policy() instead, and you can check the implementation for it and for the _PPC in: http://www.brodo.de/cpufreq_tmp/cpufreq-2.6.0-test4-update_policy and http://www.brodo.de/cpufreq_tmp/acpi-2.6.0-test4-processor_perflib Dominik