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/allwinner/sun50i-h5.dtsi#L50-L76 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 _______________________________________________ arm mailing list -- [email protected] To unsubscribe send an email to [email protected] Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/[email protected]
