From 39f94a89a90b3fa70e191716527c719e712e5076 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 3 May 2019 16:22:14 +0100 Subject: drm/i915: Assert breadcrumbs are correctly ordered in the signal handler Inside the signal handler, we expect the requests to be ordered by their breadcrumb such that no later request may be complete if we find an earlier incomplete. Add an assert to check that the next breadcrumb should not be logically before the current. v2: Move the overhanging line into its own function and reuse it after doing the insertion. Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20190503152214.26517-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/gt/intel_breadcrumbs.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c index 3cbffd400b1b..fe455f01aa65 100644 --- a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c +++ b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c @@ -80,6 +80,22 @@ static inline bool __request_completed(const struct i915_request *rq) return i915_seqno_passed(__hwsp_seqno(rq), rq->fence.seqno); } +__maybe_unused static bool +check_signal_order(struct intel_context *ce, struct i915_request *rq) +{ + if (!list_is_last(&rq->signal_link, &ce->signals) && + i915_seqno_passed(rq->fence.seqno, + list_next_entry(rq, signal_link)->fence.seqno)) + return false; + + if (!list_is_first(&rq->signal_link, &ce->signals) && + i915_seqno_passed(list_prev_entry(rq, signal_link)->fence.seqno, + rq->fence.seqno)) + return false; + + return true; +} + void intel_engine_breadcrumbs_irq(struct intel_engine_cs *engine) { struct intel_breadcrumbs *b = &engine->breadcrumbs; @@ -99,6 +115,8 @@ void intel_engine_breadcrumbs_irq(struct intel_engine_cs *engine) struct i915_request *rq = list_entry(pos, typeof(*rq), signal_link); + GEM_BUG_ON(!check_signal_order(ce, rq)); + if (!__request_completed(rq)) break; @@ -282,6 +300,7 @@ bool i915_request_enable_breadcrumb(struct i915_request *rq) list_add(&rq->signal_link, pos); if (pos == &ce->signals) /* catch transitions from empty list */ list_move_tail(&ce->signal_link, &b->signalers); + GEM_BUG_ON(!check_signal_order(ce, rq)); set_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags); } -- cgit v1.2.3