Hi Stephen, >> +/* do not passively change this clock rate during subtree rate propagation */ >> +#define CLK_NO_RATE_CHANGE_DURING_PROPAGATION BIT(14) > > Why doesn't rate locking work? Can you be more specific? What function from the API is supposed to do what I need? AFAIU, none of them is properly locking the rate during a subtree walk, but if I misread one of them, I'd be glad to drop all this. Thanks, Miquèl