Hi Daniel,
first thing: We never got to the deepest processor sleep states (C3, C4) when we originally ported coreboot for the GM45 chipset. But we didn't see a difference in power consumption back then on the Roda/RK9.
On 01.05.2016 00:55, Daniel Kulesz via coreboot wrote:
No tweaking with powertop or such
This might not be a good idea: It's not always clear which power saving options should be set by the firmware and which should be set by the os. Anyway, I don't think it makes a big impact, but could you rerun your measurements after `powertop --auto-tune`.
Nico