From mboxrd@z Thu Jan 1 00:00:00 1970 From: Al Stone Subject: Re: [PATCH v5] Force cppc_cpufreq to report values in KHz to fix user space reporting Date: Mon, 1 Aug 2016 14:07:25 -0600 Message-ID: <3ab83afa-1c91-4dcc-9206-a7a6dc3cfe83@redhat.com> References: <1469049004-19069-1-git-send-email-ahs3@redhat.com> Reply-To: ahs3@redhat.com Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1469049004-19069-1-git-send-email-ahs3@redhat.com> Sender: linux-kernel-owner@vger.kernel.org To: viresh.kumar@linaro.org, ashwin.chaugule@linaro.org, rjw@rjwysocki.net Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, Prashanth Prakash List-Id: linux-pm@vger.kernel.org On 07/20/2016 03:10 PM, Al Stone wrote: > When CPPC is being used by ACPI on arm64, user space tools such as > cpupower report CPU frequency values from sysfs that are incorrect. > > What the driver was doing was reporting the values given by ACPI tables > in whatever scale was used to provide them. However, the ACPI spec > defines the CPPC values as unitless abstract numbers. Internal kernel > structures such as struct perf_cap, in contrast, expect these values > to be in KHz. When these struct values get reported via sysfs, the > user space tools also assume they are in KHz, causing them to report > incorrect values (for example, reporting a CPU frequency of 1MHz when > it should be 1.8GHz). > [snip...] Ping? If anyone has sent comments, I have not received them. Thanks in advance for the time and effort. I know merge window can be a very busy time. -- ciao, al ----------------------------------- Al Stone Software Engineer Red Hat, Inc. ahs3@redhat.com -----------------------------------