[PATCH v6 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)

Signed-off-by: fred gao <fred.gao at intel.com>
---
 drivers/gpu/drm/i915/gvt/scheduler.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/scheduler.c b/drivers/gpu/drm/i915/gvt/scheduler.c
index 2917196..f1a048a 100644
--- a/drivers/gpu/drm/i915/gvt/scheduler.c
+++ b/drivers/gpu/drm/i915/gvt/scheduler.c
@@ -338,15 +338,17 @@ static int dispatch_workload(struct intel_vgpu_workload *workload)
 
 	ret = intel_gvt_scan_and_shadow_workload(workload);
 	if (ret)
-		goto out;
+		goto err_scan;
 
 	if (workload->prepare) {
 		ret = workload->prepare(workload);
-		if (ret)
-			goto out;
+		if (ret) {
+			engine->context_unpin(engine, shadow_ctx);
+			goto err_scan;
+		}
 	}
 
-out:
+err_scan:
 	if (ret)
 		workload->status = ret;
 
-- 
2.7.4