msm: kgsl: drm: Increased max sub-buffers allowed to 3

To permit triple buffering, number of allowed sub-buffers
was increased to 3 from 2.

Signed-off-by: Michael Street <mstreet@codeaurora.org>
Change-Id: I0d70df7b1ecad438280c9560d9b70354f3681d8f
msm: kgsl: Convert the Adreno GPU cycle counters to run free

In anticipation of allowing multiple entities to share access to the
performance counters; make the few performance counters that KGSL
uses run free.

Change-Id: Ic0dedbadbefb400b04e4f3552eed395770ddbb7b
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
msm: pm-8x60: Add early return to msm_pm_enable_retention()

If retention is already disabled, it is not necessary to send IPIs to
the running CPUs to wake them up. Insert an early return for this
scenario to reduce overhead during Krait rail voltage scaling, which
calls this API on every voltage change.

Change-Id: I5db0bafae187ff8a68488e86d4787df9c45787e4
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
msm: mdss: add ability to debug underruns

Listen for and log display underrun events for debugging purposes.

Change-Id: I09be074fd5a60266e4434acd483c74e134ba68fa
Signed-off-by: Adrian Salido-Moreno <adrianm@codeaurora.org>