diff mbox series

[5.10.y] drm/i915: Don't use stolen memory for ring buffers with LLC

Message ID 20230318004659.817361-1-John.C.Harrison@Intel.com (mailing list archive)
State New, archived
Headers show
Series [5.10.y] drm/i915: Don't use stolen memory for ring buffers with LLC | expand

Commit Message

John Harrison March 18, 2023, 12:46 a.m. UTC
From: John Harrison <John.C.Harrison@Intel.com>

Direction from hardware is that stolen memory should never be used for
ring buffer allocations on platforms with LLC. There are too many
caching pitfalls due to the way stolen memory accesses are routed. So
it is safest to just not use it.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Fixes: c58b735fc762 ("drm/i915: Allocate rings from stolen")
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/20230216011101.1909009-2-John.C.Harrison@Intel.com
(cherry picked from commit f54c1f6c697c4297f7ed94283c184acc338a5cf8)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
(cherry picked from commit 690e0ec8e63da9a29b39fedc6ed5da09c7c82651)
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
---
 drivers/gpu/drm/i915/gt/intel_ring.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/gt/intel_ring.c b/drivers/gpu/drm/i915/gt/intel_ring.c
index 69b2e5509d67..de67b2745258 100644
--- a/drivers/gpu/drm/i915/gt/intel_ring.c
+++ b/drivers/gpu/drm/i915/gt/intel_ring.c
@@ -108,7 +108,7 @@  static struct i915_vma *create_ring_vma(struct i915_ggtt *ggtt, int size)
 	struct i915_vma *vma;
 
 	obj = ERR_PTR(-ENODEV);
-	if (i915_ggtt_has_aperture(ggtt))
+	if (i915_ggtt_has_aperture(ggtt) && !HAS_LLC(i915))
 		obj = i915_gem_object_create_stolen(i915, size);
 	if (IS_ERR(obj))
 		obj = i915_gem_object_create_internal(i915, size);