[Intel-gfx] [PATCH 5/5] drm/i915: Clear the last_retired_context following a hang/reset

[Chris Wilson]

Following a hang and reset, we know that the engine is idle and all
context state has been saved or lost. Consequently, we know that the
engine is no longer referencing the last context and we can relinquish
our tracking.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala at intel.com>
Cc: Tvrtko Ursulin <tursulin at ursulin.net>
---
 drivers/gpu/drm/i915/i915_gem.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 730804ce9610..638b335e72b6 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2788,8 +2788,14 @@ void i915_gem_reset(struct drm_i915_private *dev_priv)
 
 	i915_gem_retire_requests(dev_priv);
 
-	for_each_engine(engine, dev_priv, id)
+	for_each_engine(engine, dev_priv, id) {
+		struct i915_gem_context *ctx;
+
 		i915_gem_reset_engine(engine);
+		ctx = fetch_and_zero(&engine->last_retired_context);
+		if (ctx)
+			engine->context_unpin(engine, ctx);
+	}
 
 	i915_gem_restore_fences(dev_priv);
 
-- 
2.11.0