From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Mattia Dongili" Subject: Re: [PATCH 2/2 updated] Measure transition latency at driver initialization Date: Fri, 2 Dec 2005 14:34:35 +0100 (CET) Message-ID: <4792.83.103.117.254.1133530475.squirrel@picard.linux.it> References: <11333087111183-git-send-email-malattia@linux.it> <438D9111.2000306@tremplin-utc.net> <20051130223038.GD3620@inferi.kami.home> <438E38B3.3080009@tremplin-utc.net> <20051201193147.GB4432@inferi.kami.home> <438F659B.3070103@tremplin-utc.net> <20051201233411.GA5563@inferi.kami.home> <439031F0.2090607@lifl.fr> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <439031F0.2090607@lifl.fr> 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="iso-8859-1" To: Eric Piel Cc: Eric Piel , CPUFreq Mailing List , Dominik Brodowski , davej@redhat.com On Fri, December 2, 2005 12:37 pm, Eric Piel said: > 12/02/2005 12:34 AM, Mattia Dongili wrote/a =C3=A9crit: [...] >> problematics chipsets (current testing report values ~200uSec). > Again, I though it was done... and then Ville showed that's it's plainly > wrong to assume anything with speedstep-smi: it could take up to 1 > second to change of frequency or few uSec. So we should probably back > out the smi part. > > What I propose: modify slightly the interface of speedstep_get_freqs(): > * if transition_latency is NULL, we don't try to update the transition > latency, > * otherwise we so as usual. > Then, in speedstep-smi we can call speedstep_get_freqs() with NULL, > voila :-) Ok, I had something similar in mind when thinking about creating a more general function/interface for latency measurement. We will surely need some way to disable it. Updated patch will follow soon. --=20 mattia :wq!