If two requests are on the same ring, they are explicitly ordered by the
HW. So, a submission fence is sufficient to ensure ordering when using
the new GuC submission interface. Conversely, if two requests share a
timeline and are on the same physical engine but different context this
doesn't ensure ordering on the new GuC submission interface. So, a
completion fence needs to be used to ensure ordering.

Signed-off-by: John Harrison <john.c.harri...@intel.com>
Signed-off-by: Matthew Brost <matthew.br...@intel.com>
---
 drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c |  1 -
 drivers/gpu/drm/i915/i915_request.c               | 12 ++++++++++--
 2 files changed, 10 insertions(+), 3 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 9dc1a256e185..4443cc6f5320 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -933,7 +933,6 @@ static void guc_context_sched_disable(struct intel_context 
*ce)
         * a request before we set the 'context_pending_disable' flag here.
         */
        if (unlikely(atomic_add_unless(&ce->pin_count, -2, 2))) {
-               spin_unlock_irqrestore(&ce->guc_state.lock, flags);
                return;
        }
        guc_id = prep_context_pending_disable(ce);
diff --git a/drivers/gpu/drm/i915/i915_request.c 
b/drivers/gpu/drm/i915/i915_request.c
index b48c4905d3fc..2b2b63cba06c 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -432,6 +432,7 @@ void i915_request_retire_upto(struct i915_request *rq)
 
        do {
                tmp = list_first_entry(&tl->requests, typeof(*tmp), link);
+               GEM_BUG_ON(!i915_request_completed(tmp));
        } while (i915_request_retire(tmp) && tmp != rq);
 }
 
@@ -1380,6 +1381,9 @@ i915_request_await_external(struct i915_request *rq, 
struct dma_fence *fence)
        return err;
 }
 
+static int
+i915_request_await_request(struct i915_request *to, struct i915_request *from);
+
 int
 i915_request_await_execution(struct i915_request *rq,
                             struct dma_fence *fence)
@@ -1465,7 +1469,8 @@ i915_request_await_request(struct i915_request *to, 
struct i915_request *from)
                        return ret;
        }
 
-       if (is_power_of_2(to->execution_mask | READ_ONCE(from->execution_mask)))
+       if (!intel_engine_uses_guc(to->engine) &&
+           is_power_of_2(to->execution_mask | READ_ONCE(from->execution_mask)))
                ret = await_request_submit(to, from);
        else
                ret = emit_semaphore_wait(to, from, I915_FENCE_GFP);
@@ -1626,6 +1631,8 @@ __i915_request_add_to_timeline(struct i915_request *rq)
        prev = to_request(__i915_active_fence_set(&timeline->last_request,
                                                  &rq->fence));
        if (prev && !__i915_request_is_complete(prev)) {
+               bool uses_guc = intel_engine_uses_guc(rq->engine);
+
                /*
                 * The requests are supposed to be kept in order. However,
                 * we need to be wary in case the timeline->last_request
@@ -1636,7 +1643,8 @@ __i915_request_add_to_timeline(struct i915_request *rq)
                           i915_seqno_passed(prev->fence.seqno,
                                             rq->fence.seqno));
 
-               if (is_power_of_2(READ_ONCE(prev->engine)->mask | 
rq->engine->mask))
+               if ((!uses_guc && is_power_of_2(READ_ONCE(prev->engine)->mask | 
rq->engine->mask)) ||
+                   (uses_guc && prev->context == rq->context))
                        i915_sw_fence_await_sw_fence(&rq->submit,
                                                     &prev->submit,
                                                     &rq->submitq);
-- 
2.28.0

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

Reply via email to