GPU Frequency Handling Within The Intel DRM Driver

[GreatEmerald]

Too much wasted energy, besides all or nothing isn't a smart solution

How is that wasted energy? Energy isn't used when it's sleeping. All or nothing seems like the smartest solution to me.

[bridgman]

Couple of things:

1. It takes time and energy to enter or leave sleep, so the choice between "race to idle" and intermediate clocks isn't always simple

2. Running at highest clock isn't usually the most power efficient, so you need at least three states - fastest, most efficient, and idle. The definition of "most efficient" also depends a bit on what you are doing, so you can see where this is going...