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| author | John Harrison <John.C.Harrison@Intel.com> | 2023-02-15 17:11:01 -0800 |
|---|---|---|
| committer | Jani Nikula <jani.nikula@intel.com> | 2023-02-23 13:58:22 +0200 |
| commit | 85636167e3206c3fbd52254fc432991cc4e90194 (patch) | |
| tree | aa8469ce58d99d5a41b3d85b8f35e15381c0368c | |
| parent | 690e0ec8e63da9a29b39fedc6ed5da09c7c82651 (diff) | |
| download | lwn-85636167e3206c3fbd52254fc432991cc4e90194.tar.gz lwn-85636167e3206c3fbd52254fc432991cc4e90194.zip | |
drm/i915: Don't use BAR mappings for ring buffers with LLC
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 <John.C.Harrison@Intel.com>
Fixes: 9d80841ea4c9 ("drm/i915: Allow ringbuffers to be bound anywhere")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: intel-gfx@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v4.9+
Tested-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230216011101.1909009-3-John.C.Harrison@Intel.com
(cherry picked from commit 65c08339db1ada87afd6cfe7db8e60bb4851d919)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
| -rw-r--r-- | drivers/gpu/drm/i915/gt/intel_ring.c | 4 |
1 files 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 fb1d2595392e..fb99143be98e 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); |