From: Daniele Ceraolo Spurio <[email protected]> Direction from hardware is that ring buffers should never be mapped via the BAR on systems with LLC. There are too many caching pitfalls due to the way BAR accesses are routed. So it is safest to just not use it.
Signed-off-by: John Harrison <[email protected]> Fixes: 9d80841ea4c9 ("drm/i915: Allow ringbuffers to be bound anywhere") Cc: Chris Wilson <[email protected]> Cc: Joonas Lahtinen <[email protected]> Cc: Jani Nikula <[email protected]> Cc: Rodrigo Vivi <[email protected]> Cc: Tvrtko Ursulin <[email protected]> Cc: [email protected] Cc: <[email protected]> # v4.9+ --- drivers/gpu/drm/i915/gt/intel_ring.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_ring.c b/drivers/gpu/drm/i915/gt/intel_ring.c index fb1d2595392ed..8675ec8ead353 100644 --- a/drivers/gpu/drm/i915/gt/intel_ring.c +++ b/drivers/gpu/drm/i915/gt/intel_ring.c @@ -53,7 +53,7 @@ int intel_ring_pin(struct intel_ring *ring, struct i915_gem_ww_ctx *ww) if (unlikely(ret)) goto err_unpin; - if (i915_vma_is_map_and_fenceable(vma)) { + if (i915_vma_is_map_and_fenceable(vma) && !HAS_LLC(vma->vm->i915)) { addr = (void __force *)i915_vma_pin_iomap(vma); } else { int type = i915_coherent_map_type(vma->vm->i915, vma->obj, false); @@ -98,7 +98,7 @@ void intel_ring_unpin(struct intel_ring *ring) return; i915_vma_unset_ggtt_write(vma); - if (i915_vma_is_map_and_fenceable(vma)) + if (i915_vma_is_map_and_fenceable(vma) && !HAS_LLC(vma->vm->i915)) { i915_vma_unpin_iomap(vma); else i915_gem_object_unpin_map(vma->obj); -- 2.39.1
