From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Prakash, Prashanth" Subject: Re: [PATCH 0/2] additional sysfs entries for CPPC Date: Fri, 24 Mar 2017 10:34:42 -0600 Message-ID: References: <1481763994-28146-1-git-send-email-pprakash@codeaurora.org> <72d699cd-06fb-7896-1325-5fc74c4f9888@redhat.com> <11d1f119-1dac-1045-cd86-14972982bb29@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from smtp.codeaurora.org ([198.145.29.96]:43132 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757554AbdCXQes (ORCPT ); Fri, 24 Mar 2017 12:34:48 -0400 In-Reply-To: <11d1f119-1dac-1045-cd86-14972982bb29@codeaurora.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "Rafael J. Wysocki" , Al Stone Cc: ACPI Devel Maling List , "Rafael J. Wysocki" , Alexey Klimov , Hoan Tran , Christopher Covington On 3/3/2017 11:32 AM, Prakash, Prashanth wrote: > Hi Rafael, > > On 2/13/2017 9:38 AM, Prakash, Prashanth wrote: > [...] >>>> Tested-by: Al Stone >>> I'm not actually sure about the assumption this series is based on. >>> >>> I don't see anything in the spec to guarantee that it will always be >>> safe to evaluate _CPC only once and cache its output. >> Among the Performance capabilities registers(section 8.4.7.1.1), the only >> register that can change dynamically is Guaranteed performance register. >> We are not supporting/using Guaranteed performance at the moment. >> >> Guaranteed performance Register has an associated Notify event which will be >> invoked when it changes. No such events are associated with other capabilities >> register. Similar distinction is made in the beginning of section 8.4.7.1.1: >> "Figure 8-47 outlines the static performance thresholds of the platform >> and the dynamic guaranteed performance threshold." >> >> I agree spec isn't very clear about marking these registers as static except >> that one sentence I quoted above, but there is enough in spec to guarantee >> that the capabilities we are using will not change dynamically. > Does the above sound reasonable? Any other feedback on this patch set? Gentle Ping -- Thanks, Prashanth