drm/i915/gt: Confirm the context survives execution

Repeat our sanitychecks from before execution to after execution. One
expects that if we were to see these, the gpu would already be on fire,
but the timing may be informative.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201015190816.31763-1-chris@chris-wilson.co.uk

1 files changed, 25 insertions, 12 deletions

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_pm.c b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
index f7b2e07e2229..499b09cb4acf 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_pm.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
@@ -17,6 +17,25 @@
 #include "intel_ring.h"
 #include "shmem_utils.h"
 
+static void dbg_poison_ce(struct intel_context *ce)
+{
+	if (!IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))
+		return;
+
+	if (ce->state) {
+		struct drm_i915_gem_object *obj = ce->state->obj;
+		int type = i915_coherent_map_type(ce->engine->i915);
+		void *map;
+
+		map = i915_gem_object_pin_map(obj, type);
+		if (!IS_ERR(map)) {
+			memset(map, CONTEXT_REDZONE, obj->base.size);
+			i915_gem_object_flush_map(obj);
+			i915_gem_object_unpin_map(obj);
+		}
+	}
+}
+
 static int __engine_unpark(struct intel_wakeref *wf)
 {
 	struct intel_engine_cs *engine =
@@ -32,20 +51,14 @@ static int __engine_unpark(struct intel_wakeref *wf)
 	if (ce) {
 		GEM_BUG_ON(test_bit(CONTEXT_VALID_BIT, &ce->flags));
 
+		/* Flush all pending HW writes before we touch the context */
+		while (unlikely(intel_context_inflight(ce)))
+			intel_engine_flush_submission(engine);
+
 		/* First poison the image to verify we never fully trust it */
-		if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM) && ce->state) {
-			struct drm_i915_gem_object *obj = ce->state->obj;
-			int type = i915_coherent_map_type(engine->i915);
-			void *map;
-
-			map = i915_gem_object_pin_map(obj, type);
-			if (!IS_ERR(map)) {
-				memset(map, CONTEXT_REDZONE, obj->base.size);
-				i915_gem_object_flush_map(obj);
-				i915_gem_object_unpin_map(obj);
-			}
-		}
+		dbg_poison_ce(ce);
 
+		/* Scrub the context image after our loss of control */
 		ce->ops->reset(ce);
 	}