What kernel option is needed to get /sys/devices/system/cpu/cpu0/cpufreq directory created

Hi Pavel,
I have kind of inherited my config while I have updated kernel from 3.12 .. 4.1-rt. My board used to have fixed regulators (with Media:0001-Introduce-dynamic-frequency-scaling.patch mentioned in your reference). Sysfs structures were created at least in 3.xx (without rt). Now I can verify that these structures do not exist in 4.1-rt design (DVF patched) with fixed regulator design nor in the dynamic regulator design. I do not have access to board without rt kernel at the moment.
So, it seems that DVF patch did not produce these structures. I could check defconfig you mentioned if I could find it somehow. There are some references in Ti e2e about this defconfig issue. Are they still valid telling that I should check omap2plus_defconfig instead of tisdk_am335x-evm_defconfig? If not, could you kindly attach that - or provide proper reference.
Thanks,
Matti

Matti,

Matti Kaasinen said:

I have kind of inherited my config while I have updated kernel from 3.12 .. 4.1-rt.

Can you provide a pointer from the place you have get this kernel linux-ti-staging-rt-4.1?

Matti Kaasinen said:

So, it seems that DVF patch did not produce these structures.

I do not think this Media:0001-Introduce-dynamic-frequency-scaling.patch patch is removing these sysfs entries. At which stage you have the entries in sysfs?

/sys/?/?/?/?/?

After applying the patch, do you make the below flow?

cd <kernel source directory>
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- <defconfig>
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- menuconfig
<the menuconfig interface should appear>
Select "System Type"
Select "TI OMAP Common Features"
Select "Dynamic Frequency Scaling"
Configure "Maximum supported DFS voltage (in microvolts)" (default is 1100000, or 1.1V)
Select "Exit" until you are prompted to save the configuration changes, and save them.
Rebuild the kernel.

Matti Kaasinen said:

I could check defconfig you mentioned if I could find it somehow.

You can search it with two approaches:

1. cd <kernel source directory>
    make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- help

The available defconfig files should show up.

2. cd <kernel source directory>/arch/arm/configs/

The defconfig files available are located in this directory.

Matti Kaasinen said:

There are some references in Ti e2e about this defconfig issue. Are they still valid telling that I should check omap2plus_defconfig instead of tisdk_am335x-evm_defconfig? If not, could you kindly attach that - or provide proper reference.

I am not aware of these references. Can you provide pointers to these?

Regards,
Pavel

Pavel,
I have been using Yocto project (fido) and linux-ti-staging-rt-4.1 has come from meta-ti layer.
I did not expect that patch would remove, but it could have produced these structures.
Actually I don't need that patch anymore. Fixed voltage regulators were in the first prototypes for this board. Now the problem is that I can't verify how adjustable regulators work. But I tried the procedure you suggested - in fact as it goes in yocto:
bitbake virtual/kernel -f -c menuconfig
command opens menuconfig:
But here is the problem:
There is no "Select "Dynamic Frequency Scaling" option in "TI OMAP Common Features" section.
Defconfig: there is no tisdk_am335x-evm_defconfig in /arch/arm/configs/
Meta-ti seems using configuration fragments, no configuration in single file. Only way I have found ti find the default config is to run first menuconfig and save it.

I suppose I should contact meta-arago regarding this issue.
Thanks,
Matti

Matti,

Seems like linux-ti-staging-rt-4.1 is available from the below location:

I suspect the root cause are the options selected in your .config file, which is based on <defconfig> file (if any) and menuconfig. Can you send me your .config file for analyses? It should be located in your <kernel source directory>.

Matti Kaasinen said:

I suppose I should contact meta-arago regarding this issue.

Yes, you can double check with the team there.

Also some pointers which might be in help:

- see "Getting Started with Openembedded" ppt

Regards,
Pavel

Pavel,

I tried running menuconfig once more without defconfig of my own. Therefore, it should have been brought up with internal defconfig. Results were not any better. No "Dynamic Frequency Scaling" option was available.

Please find my defconfig attached.

Thanks,

Matti

2437.defconfig.txt

Matti Kaasinen said:

I tried running menuconfig once more without defconfig of my own. Therefore, it should have been brought up with internal defconfig. Results were not any better. No "Dynamic Frequency Scaling" option was available.

For this option to be available, you need to apply the patch Media:0001-Introduce-dynamic-frequency-scaling.patch.

BR
Pavel

Pavel Botev said:

Matti Kaasinen

I tried running menuconfig once more without defconfig of my own. Therefore, it should have been brought up with internal defconfig. Results were not any better. No "Dynamic Frequency Scaling" option was available.

For this option to be available, you need to apply the patch Media:0001-Introduce-dynamic-frequency-scaling.patch.

OK, those options were for just tuning frequency, thanks

I followed your advice and it worked. It would be nice to know what changes were really needed. Thank you very much for your help.
Thanks,
Matti