On Wed, Dec 13, 2017 at 5:57 PM, Gautham R. Shenoy
[off-list ref] wrote:

From: "Gautham R. Shenoy" <redacted>

The code in powernv-cpufreq, makes the following two assumptions which
are not guaranteed by the device-tree bindings:

    1) Pstate ids are continguous: This is used in pstate_to_idx() to
       obtain the reverse map from a pstate to it's corresponding
       entry into the cpufreq frequency table.

    2) Every Pstate should always lie between the max and the min
       pstates that are explicitly reported in the device tree: This
       is used to determine whether a pstate reported by the PMSR is
       out of bounds.

Both these assumptions are unwarranted and can change on future
platforms.

While this is a good thing, I wonder if it is worth the complexity. Pstates
are contiguous because they define transitions in incremental value
of change in frequency and I can't see how this can be broken in the
future?

Balbir Singh.