From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtpauth.hypersurf.com (smtpauth.hypersurf.com [209.237.0.8]) by ozlabs.org (Postfix) with ESMTP id 7A1E8DDDEF for ; Sun, 27 Apr 2008 19:51:03 +1000 (EST) Received: from [192.168.1.37] (node93.73.251.72.1dial.com [72.251.73.93]) (authenticated bits=0) by smtpauth.hypersurf.com (8.14.2/8.14.2) with ESMTP id m3R9nBXt048592 for ; Sun, 27 Apr 2008 02:50:52 -0700 (PDT) Message-ID: <48145709.9020809@hypersurf.com> Date: Sun, 27 Apr 2008 03:35:54 -0700 From: Kevin Diggs MIME-Version: 1.0 To: linuxppc-dev@ozlabs.org Subject: Re: get_cycles() References: <4812DFA3.6090106@hypersurf.com> <20080426.001102.65527296.davem@davemloft.net> <4813E74B.1020506@hypersurf.com> <20080426.202135.145326755.davem@davemloft.net> In-Reply-To: <20080426.202135.145326755.davem@davemloft.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , David Miller wrote: > From: Kevin Diggs > Date: Sat, 26 Apr 2008 19:39:07 -0700 > > >>This looks pretty cool ... but I don't want to create a dependency on >>hrtimer. > > > It doesn't create such a dependency. > > We use it unconditionally in the generic networking. > > Please don't use platform specific interfaces if you don't have to. > You're be insulated from so many things. > I'm working on a cpufreq driver for the 750GX so I don't think I have to worry about being to platform specific. Would a compile time configuration be a good idea (hrtimer or get_cycles() assisted timing)? In the 2.4 code I just used a timer 2 ticks in the future to be certain I did not go under the 100 us PLL lock delay. I was trying to see if I could cut the latency down. What about using OF? Isn't there a timebase property for the cpus? Thoughts? kevin