[PATCH] drm/i915: Remove unnecessary memory quiescing for aux inval

[Nirmoy Das]

i915 already does memory quiesce before signaling
breadcrumb so remove extra memory quiescing for aux
invalidation which can cause unnecessary side effects.

Signed-off-by: Nirmoy Das <nirmoy.das at intel.com>
---
 drivers/gpu/drm/i915/gt/gen8_engine_cs.c | 28 +++++++++++++-----------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
index 0143445dba83..41d8078b040a 100644
--- a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
@@ -248,11 +248,7 @@ int gen12_emit_flush_rcs(struct i915_request *rq, u32 mode)
 {
 	struct intel_engine_cs *engine = rq->engine;
 
-	/*
-	 * On Aux CCS platforms the invalidation of the Aux
-	 * table requires quiescing memory traffic beforehand
-	 */
-	if (mode & EMIT_FLUSH || gen12_needs_ccs_aux_inv(engine)) {
+	if (mode & EMIT_FLUSH) {
 		u32 bit_group_0 = 0;
 		u32 bit_group_1 = 0;
 		int err;
@@ -264,13 +260,6 @@ int gen12_emit_flush_rcs(struct i915_request *rq, u32 mode)
 
 		bit_group_0 |= PIPE_CONTROL0_HDC_PIPELINE_FLUSH;
 
-		/*
-		 * When required, in MTL and beyond platforms we
-		 * need to set the CCS_FLUSH bit in the pipe control
-		 */
-		if (GRAPHICS_VER_FULL(rq->i915) >= IP_VER(12, 70))
-			bit_group_0 |= PIPE_CONTROL_CCS_FLUSH;
-
 		bit_group_1 |= PIPE_CONTROL_TILE_CACHE_FLUSH;
 		bit_group_1 |= PIPE_CONTROL_FLUSH_L3;
 		bit_group_1 |= PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH;
@@ -800,6 +789,7 @@ u32 *gen12_emit_fini_breadcrumb_rcs(struct i915_request *rq, u32 *cs)
 {
 	struct drm_i915_private *i915 = rq->i915;
 	struct intel_gt *gt = rq->engine->gt;
+	u32 bit_group_0 = PIPE_CONTROL0_HDC_PIPELINE_FLUSH;
 	u32 flags = (PIPE_CONTROL_CS_STALL |
 		     PIPE_CONTROL_TLB_INVALIDATE |
 		     PIPE_CONTROL_TILE_CACHE_FLUSH |
@@ -824,7 +814,19 @@ u32 *gen12_emit_fini_breadcrumb_rcs(struct i915_request *rq, u32 *cs)
 	else if (rq->engine->class == COMPUTE_CLASS)
 		flags &= ~PIPE_CONTROL_3D_ENGINE_FLAGS;
 
-	cs = gen12_emit_pipe_control(cs, PIPE_CONTROL0_HDC_PIPELINE_FLUSH, flags, 0);
+	/*
+	 * On Aux CCS platforms the invalidation of the Aux
+	 * table requires quiescing memory traffic beforehand.
+	 * gen12_emit_fini_breadcrumb_rcs() does this for us as
+	 * all memory traffic has to be completed before we signal
+	 * the breadcrumb. In MTL and beyond platforms, we need to also
+	 * add CCS_FLUSH bit in the pipe control for that purpose.
+	 */
+
+	if (GRAPHICS_VER_FULL(rq->i915) >= IP_VER(12, 70))
+		bit_group_0 |= PIPE_CONTROL_CCS_FLUSH;
+
+	cs = gen12_emit_pipe_control(cs, bit_group_0, flags, 0);
 
 	/*XXX: Look at gen8_emit_fini_breadcrumb_rcs */
 	cs = gen12_emit_ggtt_write_rcs(cs,
-- 
2.41.0