controlling CPU speed on N800/N810

controlling CPU speed on N800/N810

[Kalle Valo]

Hello,

I'm about to do some throughput measurements with stlc45xx (the open
wi-fi driver) on Nokia N800. Now I would like see the current CPU
speed. I also liked to change it, because I believe it will have an
affect on throughput.

I tried cpufreq but it wasn't very helpful:

/sys/devices/system/cpu/cpu0/cpufreq# cat cpuinfo_cur_freq 
<unknown>/sys/devices/system/cpu/cpu0/cpufreq# 

Is it possible to change CPU speed in latest linux-omap kernels?

I'm using N800 and omap-2.6.29 branch from linux-omap tree.

-- 
Kalle Valo

Re: controlling CPU speed on N800/N810

[Igor Stoppa]

Hi,
On Sat, 2009-04-04 at 09:58 +0200, ext Kalle Valo wrote:

> Is it possible to change CPU speed in latest linux-omap kernels?

afaik, no, but that makes your job easier, the ARM clock should be
330MHz - at least that's what TI supports and recommends when also the
DSP is in use


-- 

Cheers, Igor

---

Igor Stoppa
Maemo Software - Nokia Devices R&D - Helsinki

Re: controlling CPU speed on N800/N810

[Kalle Valo]

Igor Stoppa <igor.stoppa@nokia.com> writes:

> Hi,
> On Sat, 2009-04-04 at 09:58 +0200, ext Kalle Valo wrote:
>
>> Is it possible to change CPU speed in latest linux-omap kernels?
>
> afaik, no, but that makes your job easier, the ARM clock should be
> 330MHz - at least that's what TI supports and recommends when also the
> DSP is in use

Ok, thanks for the info. 

I got better wi-fi throughput with nokia 2.6.21 kernel compared to
linux-omap kernels, but the CPU speed difference will most likely
explain that. I'm assuming that DVFS increased the CPU speed over 400
MHz when running throughtput tests on nokia 2.6.21 kernel.

If anyone have hints or pointers how to overclock linux-omap kernels,
I'm all ears :)

-- 
Kalle Valo