[PATCH V2] cpuidle/powernv: Read target_residency value of idle states from DT if available

[Stewart Smith]

Preeti U Murthy <preeti at linux.vnet.ibm.com> writes:
> The device tree now exposes the residency values for different idle states. Read
> these values instead of calculating residency from the latency values. The values
> exposed in the DT are validated for optimal power efficiency. However to maintain
> compatibility with the older firmware code which does not expose residency
> values, use default values as a fallback mechanism. While at it, handle some
> cleanups.

>From a "I just merged the patch that exports these values from firmware"
point of view, using them and falling back looks good.

(I find the hardcoding of snooze in the driver a bit odd, as is the
hardcoding of max power states to 8 - which could bite us in the future
if a future processor has more states... but these aren't problems with
this patch)

Acked-by: Stewart Smith <stewart at linux.vnet.ibm.com>