The tsc clock source keeps getting marked unstable and falls back to using acpi_pm on kernel This is directly linked to using cpu frequencing scaling. If I leave default governer as performace is fine, second I set to ondemand or anything the changes the current frequency the unstable msg appears.

What I what to know is:

Is this normal and expected ? If so ignoring the msg is fine.

Will this cause a problem at the point a different clock source is used ?

Can I set the system to always use acpi_pm rather than the tsc
(I always use cpu frequency to save power as cpu use is low) and if so how?

I have had a good google around but can't find clear answers. So please someone put my mind at rest.