drm/i915: Don't use stolen memory for ring buffers with LLC

commit 690e0ec8e6 upstream.

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: c58b735fc7 ("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 f54c1f6c69)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
John Harrison
2023-02-15 17:11:00 -08:00
committed by Greg Kroah-Hartman
parent b4a798374f
commit 8f27d43217
+1 -1
View File
@@ -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);