[Intel-gfx] [PATCH] drm/i915: Add engine idle check for CI

[Mika Kuoppala]

Assert for hardware idleness when we assign to execlist port,
if for some reason we get off the tracks on sw tracking.

Cc: Chris Wilson <chris at chris-wilson.co.uk>
Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
---
 drivers/gpu/drm/i915/intel_engine_cs.c  | 10 ++++++++++
 drivers/gpu/drm/i915/intel_lrc.c        |  4 +++-
 drivers/gpu/drm/i915/intel_ringbuffer.h |  1 +
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index 69a6416..ba09420 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -524,3 +524,13 @@ void intel_engine_get_instdone(struct intel_engine_cs *engine,
 		break;
 	}
 }
+
+bool intel_engine_idle(struct intel_engine_cs *engine)
+{
+	struct drm_i915_private *dev_priv = engine->i915;
+
+	if (INTEL_GEN(engine->i915) > 2)
+		return I915_READ_MODE(engine) & MODE_IDLE;
+
+	return true;
+}
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index b21dbd4..3d909e3 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -347,9 +347,11 @@ static void execlists_submit_ports(struct intel_engine_cs *engine)
 	u64 desc[2];
 
 	GEM_BUG_ON(port[0].count > 1);
-	if (!port[0].count)
+	if (!port[0].count) {
+		GEM_BUG_ON(!intel_engine_idle(engine));
 		execlists_context_status_change(port[0].request,
 						INTEL_CONTEXT_SCHEDULE_IN);
+	}
 	desc[0] = execlists_update_context(port[0].request);
 	GEM_BUG_ONLY(port[0].context_id = upper_32_bits(desc[0]));
 	port[0].count++;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 896838c..a319df9 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -603,6 +603,7 @@ bool intel_engine_add_wait(struct intel_engine_cs *engine,
 void intel_engine_remove_wait(struct intel_engine_cs *engine,
 			      struct intel_wait *wait);
 void intel_engine_enable_signaling(struct drm_i915_gem_request *request);
+bool intel_engine_idle(struct intel_engine_cs *engine);
 
 static inline bool intel_engine_has_waiter(const struct intel_engine_cs *engine)
 {
-- 
2.7.4