[fedora-arm] Re: Orange Pi PC 2 (Allwinner H5) cpu governor support?
On 1/5/19 3:09 PM, Major Hayden wrote:
I recently got an Orange Pi PC 2 and Fedora 29 is working quite well
on it. The only issue I'm having is occasional RCU stalls and I've read some
reports that reducing the maximum CPU frequency can improve this a bit on these boards.
However, I can't find any cpufreq-related tunables for any of the CPUs:
# ls -al /sys/devices/system/cpu/cpufreq/
total 0
drwxr-xr-x. 2 root root 0 Jan 5 15:42 .
drwxr-xr-x. 10 root root 0 Jun 22 2018 ..
It looks like everything related to SUNXI or CPUFREQ in the kernel config is either a
module or built into the kernel. I've found some other threads talking about ensuring
the right CONFIG_REGULATOR_* options are enabled, but I'm not sure what the correct
one might be for this board.
Am I missing something important here to regulate the CPU frequency? Thanks!
After more digging, I found that the device tree has no 'operating-points' for the
CPU:
https://github.com/torvalds/linux/blob/master/arch/arm64/boot/dts/allwinn...
It appears that cpufreq_dt has no idea how to handle CPU frequencies without knowing the
voltage/frequency relationship. Is this something that the vendor must provide?
--
Major Hayden