Alan Jenkins wrote: >> I notice that the "states:" is empty??? >> > That confirms what powertop said. It's what I would expect.
yeah the bios doesn't export C-states to the OS. > However, even with the fix, my BIOS doesn't provide any *C* state > information. That's because the BIOS manages the different non-zero > C-states itself, and linux doesn't see them. > > This is known as "C1E", that is only true for AMD systems btw; "C1E" is defined by AMD to be "we'll break all the rules and pick the C-state ourselves", on Intel systems C1E is "we'll go to the lowest voltage in idle". I'm not trying to be evil towards AMD by saying "we'll break all the rules", they really do break all the rules around C-states. (There are guarantees about what the OS can expect for the different C-states, C3 for example is very different from C2 and that again is very different from C1. This automagic going deeper gives you C3 behavior even though only C1 is asked for. This broke Linux quite severely and is the cause of many workarounds in the tickless idle code already, and I suspect more are to come still) _______________________________________________ Power mailing list [email protected] http://www.bughost.org/mailman/listinfo/power
