[PATCH 5.15.y] drm/i915/gt: Cleanup partial engine discovery failures

[Zhi Yang]

From: Chris Wilson <chris.p.wilson@xxxxxxxxx>

commit 78a033433a5ae4fee85511ee075bc9a48312c79e upstream.

If we abort driver initialisation in the middle of gt/engine discovery,
some engines will be fully setup and some not. Those incompletely setup
engines only have 'engine->release == NULL' and so will leak any of the
common objects allocated.

v2:
 - Drop the destroy_pinned_context() helper for now.  It's not really
   worth it with just a single callsite at the moment.  (Janusz)

Signed-off-by: Chris Wilson <chris.p.wilson@xxxxxxxxx>
Cc: Janusz Krzysztofik <janusz.krzysztofik@xxxxxxxxxxxxxxx>
Signed-off-by: Matt Roper <matthew.d.roper@xxxxxxxxx>
Reviewed-by: Janusz Krzysztofik <janusz.krzysztofik@xxxxxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20220915232654.3283095-2-matthew.d.roper@xxxxxxxxx
Signed-off-by: Zhi Yang <Zhi.Yang@xxxxxxxxxxxxx>
Signed-off-by: He Zhe <zhe.he@xxxxxxxxxxxxx>
---
Build test passed.
---
 drivers/gpu/drm/i915/gt/intel_engine_cs.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
index eb99441e0ada..42cb3ad04d89 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -983,8 +983,13 @@ int intel_engines_init(struct intel_gt *gt)
 			return err;
 
 		err = setup(engine);
-		if (err)
+		if (err) {
+			intel_engine_cleanup_common(engine);
 			return err;
+		}
+
+		/* The backend should now be responsible for cleanup */
+		GEM_BUG_ON(engine->release == NULL);
 
 		err = engine_init_common(engine);
 		if (err)
-- 
2.34.1