[Intel-gfx] [PATCH 0/3] Three small patches to ringbuffer calculations

[Dave Gordon]

[PATCH 1/3] drm/i915: use effective_size for ringbuffer calculations

    When calculating the available space in a ringbuffer, we should
    use the effective_size rather than the true size of the ring.

[PATCH 2/3] drm/i915: recheck ringspace after wait+retire

    When a ringbuffer is nearly full, we often wait for some request
    to complete and so free up some ringspace. This code checks that
    we actually got at least as much space as we expected and need.

[PATCH 3/3] drm/i915: Track & check calls to intel(_logical)_ring_{begin,advance}

    Check that these functions are used in a logically consistent manner.

I've dropped the patch to allow nested begin/advance pairs; instead
we will create a pre-allocate/reserve call as part of the scheduler
or preemption work.