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From: tony@bakeyournoodle.com (Tony Breeds)
To: Kevin Diggs <kevdig@hypersurf.com>
Cc: linuxppc-dev@ozlabs.org
Subject: Re: get_cycles()
Date: Mon, 28 Apr 2008 14:38:05 +1000	[thread overview]
Message-ID: <20080428043805.GY20457@bakeyournoodle.com> (raw)
In-Reply-To: <48145709.9020809@hypersurf.com>

On Sun, Apr 27, 2008 at 03:35:54AM -0700, Kevin Diggs wrote:

> 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)?

Save yourself the pain, and use the hrtimers infrastructure.
 
> 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?

Sure, If you really don't want to use the infrastructure that's there
feel free to duplicate portions of arch/powerpc/kernel/time.c and
kernel/time/* into your cpufreq driver.

Yours Tony

  linux.conf.au    http://www.marchsouth.org/
  Jan 19 - 24 2009 The Australian Linux Technical Conference!

      reply	other threads:[~2008-04-28  4:38 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-04-26  7:54 get_cycles() Kevin Diggs
2008-04-26  7:11 ` get_cycles() David Miller
2008-04-27  2:39   ` get_cycles() Kevin Diggs
2008-04-27  3:21     ` get_cycles() David Miller
2008-04-27 10:35       ` get_cycles() Kevin Diggs
2008-04-28  4:38         ` Tony Breeds [this message]

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