testing cpufreq on the beagleboard

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1

Hi,

Rajendra Nayak posted a cpufreq patch for SDP to the linux-omap
mailinglist and I tried to adapt it to beagleboard[1], the resulting
uImage is at[2]. The sad news is that it doesn't work, there's no sign
of cpufreq at runtime :frowning:
Could people have a look at the patch and/or test the uImage on their
board? The defconfig can be gotten from /proc/config.gz.

regards,

Koen

[1] http://ewi546.ewi.utwente.nl/~koen/01-beagle-cpufreq.diff
[2] http://ewi546.ewi.utwente.nl/~koen/uImage-2.6.26-r60-beagleboard.bin

2

Koen,

I am not so familiar with GIT kernel. Based on my experience with TI kernel - one possibility is that you need to remove any other constraints on VDD1 OPP so that cpufreq changes will take effect. What governor you have enabled by default ?

Following may not be applicable to GIT kernel, but you should be able to find substitutes

For eg:-
"cat /proc/shared_resources" will show resource levels on different resources - resource framework will choose the highest level request, so if constraint framework and cpufreq frameworks are active together, constraint framework may override cpufreq request.

echo 1 > /sys/power/vdd1_opp_value //Remove constraints on OPP1

echo 125000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed //Assuming you are using user space governor

if ondemand governor is enabled, it will automatically drop to 125 MHz.

Regards,
Pratheesh

3

Koen,

I am not so familiar with GIT kernel. Based on my experience with TI kernel - one possibility is that you need to remove any other constraints on VDD1 OPP so that cpufreq changes will take effect. What governor you have enabled by default ?

Following may not be applicable to GIT kernel, but you should be able to find substitutes

For eg:-
"cat /proc/shared_resources" will show resource levels on different resources - resource framework will choose the highest level request, so if constraint framework and cpufreq frameworks are active together, constraint framework may override cpufreq request.

echo 1 > /sys/power/vdd1_opp_value //Remove constraints on OPP1

echo 125000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed //Assuming you are using user space governor

if ondemand governor is enabled, it will automatically drop to 125 MHz.

The problems is that I don't even get cpufreq sysfs nodes, so it seems
it doesn't get enabled at all. It would be interesting to see if
people with rev B boards get them with the uImage I linked.

regards,

Koen