[Intel-gfx] [PATCH v3 2/5] drm/i915/gt: Ensure memory quiesced before invalidation

[Andi Shyti <andi.shyti@linux.intel.com>]

From: Jonathan Cavitt <jonathan.cavitt@intel.com>

All memory traffic must be quiesced before requesting
an aux invalidation on platforms that use Aux CCS.

Fixes: 972282c4cf24 ("drm/i915/gen12: Add aux table invalidate for all engines")
Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Cc: <stable@vger.kernel.org> # v5.8+
---
 drivers/gpu/drm/i915/gt/gen8_engine_cs.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
index 563efee055602..bee3b7dc595cf 100644
--- a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
@@ -202,6 +202,13 @@ int gen12_emit_flush_rcs(struct i915_request *rq, u32 mode)
 {
 	struct intel_engine_cs *engine = rq->engine;
 
+	/*
+	 * Aux invalidations on Aux CCS platforms require
+	 * memory traffic is quiesced prior.
+	 */
+	if ((mode & EMIT_INVALIDATE) && !HAS_FLAT_CCS(engine->i915))
+		mode |= EMIT_FLUSH;
+
 	if (mode & EMIT_FLUSH) {
 		u32 flags = 0;
 		int err;
-- 
2.40.1