Re: [Gumstix-users] Re: Re: CPUfreq & power saving questions

[Craig H. <cr...@gu...>]

On Jan 31, 2006, at 9:32 AM, miles wrote:

> It looks like the drivers are there, since as you suggest the sys  
> entries come and go. But but only performance is ever used?  
> Performance isn't even compiled in.

 From what you're showing below, it looks like the "echo $GOVERNOR >  
scaling_governor" is working, but just not updating the string which  
can then be read back from that same node.  I'd try doing the same  
thing under 2.6.15 -- it's quite likely working better there.  Note  
that it's a really, really bad idea to use the governors like  
"ondemand" which do a lot of frequency switches, as it really makes  
it likely you'll run into the PXA255 erratum.

> # uname -a
> Linux gumstix 2.6.11gum #6 Mon Jan 30 11:42:32 PST 2006 armv5tel  
> unknown
> # pwd
> /sys/devices/system/cpu/cpu0/cpufreq
> # ls
> affected_cpus                scaling_driver	 
> cpuinfo_max_freq             scaling_governor
> cpuinfo_min_freq             scaling_max_freq	 
> scaling_available_governors  scaling_min_freq
> scaling_cur_freq             scaling_setspeed
> # cat scaling_available_governors
> ondemand userspace
> # cat scaling_governor
> performance
> # echo ondemand > scaling_governor
> # cat scaling_governor
> performance
> # ls
> affected_cpus                scaling_cur_freq	 
> cpuinfo_max_freq             scaling_driver
> cpuinfo_min_freq             scaling_governor	 
> ondemand                     scaling_max_freq
> scaling_available_governors  scaling_min_freq
> # echo userspace > scaling_governor
> # ls
> affected_cpus                scaling_driver	 
> cpuinfo_max_freq             scaling_governor
> cpuinfo_min_freq             scaling_max_freq	 
> scaling_available_governors  scaling_min_freq
> scaling_cur_freq             scaling_setspeed
> # cat scaling_governor
> performance
> # cat scaling_min_freq
> 398131
> # cat scaling_max_freq
> 398131
> # cat scaling_cur_freq
> 398131
> # cat cpuinfo_min_freq
> 99533
> # echo 99533 > scaling_setspeed
> # cat scaling_setspeed
> 398131
> # cat scaling_cur_freq
> 398131
>
>
>
> -------------------------------------------------------
> This SF.net email is sponsored by: Splunk Inc. Do you grep through  
> log files
> for problems?  Stop!  Download the new AJAX search engine that makes
> searching your log files as easy as surfing the  web.  DOWNLOAD  
> SPLUNK!
> http://sel.as-us.falkag.net/sel? 
> cmd=lnk&kid=103432&bid=230486&dat=121642
> _______________________________________________
> gumstix-users mailing list
> gum...@li...
> https://lists.sourceforge.net/lists/listinfo/gumstix-users