drm/msm: Change the priority order of the ringbuffers

When we first did preemption the priority was set at submission
time. In order to be properly backwards compatible we made ring id 0
the lowest priority ring so that when a legacy app made a submission
it didn't get itself onto the highest priority ring by accident.

Now that we set the priority with submitqueues this is no longer
a concern and ordering priorities this way goes against long
standing convention in similar GPU drivers.

Declare a flag day and invert the priority algorithm so that
priority '0' is the highest priority and it descends from there.
The lowest prority ring is 'number of rings - 1' where the number
of active rings can be acquired through a parameter query of
MSM_PARAM_NR_RINGS.

This change also ensures that the legacy submitqueue id '0' will
use the next-to-lowest ring buffer by default for legacy
submissions.

Change-Id: Ic0dedbadeea522e4f07babc4395cbf5fb7143fe3
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>

0 files changed, 0 insertions, 0 deletions