[PATCH 03/22] drm/i915/guc: Unwind context requests in reverse order

[Matthew Brost]

When unwinding requests on a reset context, if other requests in the
context are in the priority list the requests could be resubmitted out
of seqno order. Traverse the list of active requests in reverse and
append to the head of the priority list to fix this.

Fixes: eb5e7da736f3 ("drm/i915/guc: Reset implementation for new GuC interface")
Signed-off-by: Matthew Brost <matthew.br...@intel.com>
Cc: <sta...@vger.kernel.org>
---
 drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c 
b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
index b5d3972ae164..bc51caba50d0 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -799,9 +799,9 @@ __unwind_incomplete_requests(struct intel_context *ce)
 
        spin_lock_irqsave(&sched_engine->lock, flags);
        spin_lock(&ce->guc_active.lock);
-       list_for_each_entry_safe(rq, rn,
-                                &ce->guc_active.requests,
-                                sched.link) {
+       list_for_each_entry_safe_reverse(rq, rn,
+                                        &ce->guc_active.requests,
+                                        sched.link) {
                if (i915_request_completed(rq))
                        continue;
 
@@ -818,7 +818,7 @@ __unwind_incomplete_requests(struct intel_context *ce)
                }
                GEM_BUG_ON(i915_sched_engine_is_empty(sched_engine));
 
-               list_add_tail(&rq->sched.link, pl);
+               list_add(&rq->sched.link, pl);
                set_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags);
 
                spin_lock(&ce->guc_active.lock);
-- 
2.32.0