From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: cpufreq and boost with amd ryzen Date: Wed, 05 Jul 2017 13:01:32 +0200 Message-ID: <2081647.Fs5kDZcm2E@aspire.rjw.lan> References: <20170705041758.GJ3532@vireshk-i7> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: Received: from cloudserver094114.home.net.pl ([79.96.170.134]:56065 "EHLO cloudserver094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751755AbdGELJN (ORCPT ); Wed, 5 Jul 2017 07:09:13 -0400 In-Reply-To: <20170705041758.GJ3532@vireshk-i7> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Viresh Kumar Cc: Sergio P , "Rafael J. Wysocki" , Linux PM list On Wednesday, July 05, 2017 09:47:58 AM Viresh Kumar wrote: > +Rafael, > > On 04-07-17, 16:38, Sergio P wrote: > > To be honest, I am not very familiar on how to debug the kernel. > > > > My guess would be that X86_FEATURE_CPB is not being detected correctly > > for Ryzen family in the CPUID registers, and it returns early from > > acpi_cpufreq_boost_init(). Also, CPB was a feature in earlier AMD > > processors, but now in the new Ryzen family, I'm not sure if it's > > called something else and perhaps defined in a different CPUID bit. > > @Rafael: Do you have any idea about the new Ryzen family or how to get boost > working on them ? Not from the top of my head, I need to look into the code. In any case, IIRC, the boost and cpb attributes are mutually exclusive, so you won't see the former if you see the latter. I'm not sure how we decide which one to expose, though. Thanks, Rafael