From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon, 25 Jun 2018 11:06:03 +0100
Subject: drm/i915/execlists: Check for ce->state before destroy
Git-commit: dd12c6ca5b45fd54e80c1424b11a5a25ad913dbb
Patch-mainline: v4.19-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

As we may cancel the ce->state allocation during context pinning (but
crucially after we mark ce as operational), that means we may be asked
to destroy a nonexistent ce->state. Given the choice in handing a
complex error path on pinning, and just ignoring the lack of state in
destroy, choice the latter for simplicity.

Reported-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180625100604.22598-1-chris@chris-wilson.co.uk

Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/i915/intel_lrc.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -1337,9 +1337,11 @@ static void execlists_schedule(struct i9
 
 static void execlists_context_destroy(struct intel_context *ce)
 {
-	GEM_BUG_ON(!ce->state);
 	GEM_BUG_ON(ce->pin_count);
 
+	if (!ce->state)
+		return;
+
 	intel_ring_free(ce->ring);
 	__i915_gem_object_release_unless_active(ce->state->obj);
 }