I just checked 100us on Pinebook one more time, the boot process is stuck at "root on sd0a [...]" - I think it's the first time when CPU clock is set. Lowest value (round to 100) that was working for me was 200us.
But if you think it should be smaller (even 1us like on H3/H5 in this driver already) then it's fine with me. I can use different value for this specific machine (I didn't have any problems with 1us on A64+ if I can recall). It's not a problem to modify one value if the code is already there, which would be nice. Thank you for looking into the patch, -- Krystian
