CPU frequency still stuck at lowest frequency with intel_pstate on 4.9

[Taylor Kline <taylor.kline@utexas.edu>]

Hello,

Running kernel 4.9.2-2 and I am still stuck at 800MHz if I use the
intel_pstate driver on a Dell XPS 15 (9550) with the latest BIOS
(1/23/2017).

How can I contribute to a diagnosis & fix of this? intel_pstate is
pretty important for Sandy Bridge CPUs and above.

I filed Bug#850053 with 4.8.11-1 but I expected it to be fixed in 4.9
because of: https://bugzilla.kernel.org/show_bug.cgi?id=90041

However, it looks like it's not fixed.

Regards,
-Taylor