drm/i915/gt: Take responsibility for engine->release as the last step

In order to avoid a double cleanup on error, take ownership of
engine->release past the point of no [error] return.
Reported-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Fixes: e26b6d43 ("drm/i915/gt: Pull GT initialisation under intel_gt_init()")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Tested-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200107143118.3288995-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gt/intel_lrc.c

@@ -3925,7 +3925,6 @@ logical_ring_default_vfuncs(struct intel_engine_cs *engine)
 {
 	/* Default vfuncs which can be overriden by each engine. */
 
-	engine->release = execlists_release;
 	engine->resume = execlists_resume;
 
 	engine->cops = &execlists_context_ops;
@@ -4040,6 +4039,9 @@ int intel_execlists_submission_setup(struct intel_engine_cs *engine)
 
 	reset_csb_pointers(engine);
 
+	/* Finally, take ownership and responsibility for cleanup! */
+	engine->release = execlists_release;
+
 	return 0;
 }
 

drivers/gpu/drm/i915/gt/intel_ring_submission.c

@@ -1840,8 +1840,6 @@ static void setup_common(struct intel_engine_cs *engine)
 
 	setup_irq(engine);
 
-	engine->release = ring_release;
-
 	engine->resume = xcs_resume;
 	engine->reset.prepare = reset_prepare;
 	engine->reset.rewind = reset_rewind;
@@ -2007,6 +2005,9 @@ int intel_ring_submission_setup(struct intel_engine_cs *engine)
 
 	GEM_BUG_ON(timeline->hwsp_ggtt != engine->status_page.vma);
 
+	/* Finally, take ownership and responsibility for cleanup! */
+	engine->release = ring_release;
+
 	return 0;
 
 err_ring: