On 8/18/2021 11:16 PM, Matthew Brost wrote:
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.brost@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
---
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 32c414aa9009..9ca0ba4ea85a 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -805,9 +805,9 @@ __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))
The execlists unwind function has a list_del if the request is
completed. Any reason not to do that here?
continue;
@@ -824,7 +824,7 @@ __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);
Since you always do both list_del and list_add and it doesn't look like
you use the fact that the list is empty between the 2 calls, you can
merge them in a list_move.
Apart from these nits, the change to navigate the list in reverse and
append here at the top LGTM.
Daniele
set_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags);
spin_lock(&ce->guc_active.lock);
