[PATCH v7 5/6] drm/i915/gvt: Refine error handling in dispatch_workload

[fred gao]

When an error occurs in dispatch_workload, this patch is to do the
proper cleanup and rollback to the original states before the workload
is abandoned.

v2:
- split the mixed several error paths for better review. (Zhenyu)

v3:
- original PTR_ERR(cs) is good and code cleanup. (Zhenyu)

v4:
- reuse the existing i915_add_request for error handling. (Zhenyu)

v5:
- remove the duplicate error handling release_shadow_wa_ctx and
  move the engine->context_unpin upper. (Zhenyu)

v6:
- keep the old label "out". (Zhenyu)

Signed-off-by: fred gao <fred.gao at intel.com>
---
 drivers/gpu/drm/i915/gvt/scheduler.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gvt/scheduler.c b/drivers/gpu/drm/i915/gvt/scheduler.c
index 2917196..6fb9b58 100644
--- a/drivers/gpu/drm/i915/gvt/scheduler.c
+++ b/drivers/gpu/drm/i915/gvt/scheduler.c
@@ -342,8 +342,10 @@ static int dispatch_workload(struct intel_vgpu_workload *workload)
 
 	if (workload->prepare) {
 		ret = workload->prepare(workload);
-		if (ret)
+		if (ret) {
+			engine->context_unpin(engine, shadow_ctx);
 			goto out;
+		}
 	}
 
 out:
-- 
2.7.4