diff options
Diffstat (limited to 'drivers/gpu/drm/i915/i915_gem_request.c')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_gem_request.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c index e2ec42b2bf24..126cd13abf54 100644 --- a/drivers/gpu/drm/i915/i915_gem_request.c +++ b/drivers/gpu/drm/i915/i915_gem_request.c @@ -283,10 +283,18 @@ static void advance_ring(struct drm_i915_gem_request *request) * Note this requires that we are always called in request * completion order. */ - if (list_is_last(&request->ring_link, &request->ring->request_list)) - tail = request->ring->tail; - else + if (list_is_last(&request->ring_link, &request->ring->request_list)) { + /* We may race here with execlists resubmitting this request + * as we retire it. The resubmission will move the ring->tail + * forwards (to request->wa_tail). We either read the + * current value that was written to hw, or the value that + * is just about to be. Either works, if we miss the last two + * noops - they are safe to be replayed on a reset. + */ + tail = READ_ONCE(request->ring->tail); + } else { tail = request->postfix; + } list_del(&request->ring_link); request->ring->head = tail; @@ -651,7 +659,7 @@ i915_gem_request_alloc(struct intel_engine_cs *engine, * GPU processing the request, we never over-estimate the * position of the head. */ - req->head = req->ring->tail; + req->head = req->ring->emit; /* Check that we didn't interrupt ourselves with a new request */ GEM_BUG_ON(req->timeline->seqno != req->fence.seqno); |