@@ -3703,6 +3703,9 @@ static int wait_for_engines(struct drm_i915_private *i915)
int i915_gem_wait_for_idle(struct drm_i915_private *i915, unsigned int flags)
{
+ GEM_TRACE("flags=%x (%s)\n",
+ flags, flags & I915_WAIT_LOCKED ? "locked" : "unlocked");
+
/* If the device is asleep, we have no requests outstanding */
if (!READ_ONCE(i915->gt.awake))
return 0;
@@ -3719,6 +3722,7 @@ int i915_gem_wait_for_idle(struct drm_i915_private *i915, unsigned int flags)
return err;
}
i915_retire_requests(i915);
+ GEM_BUG_ON(i915->gt.active_requests);
return wait_for_engines(i915);
} else {
@@ -4901,6 +4905,7 @@ static void assert_kernel_context_is_current(struct drm_i915_private *i915)
struct intel_engine_cs *engine;
enum intel_engine_id id;
+ GEM_BUG_ON(i915->gt.active_requests);
for_each_engine(engine, i915, id) {
GEM_BUG_ON(__i915_gem_active_peek(&engine->timeline.last_request));
GEM_BUG_ON(engine->last_retired_context->gem_context != kctx);
@@ -4932,6 +4937,8 @@ int i915_gem_suspend(struct drm_i915_private *dev_priv)
struct drm_device *dev = &dev_priv->drm;
int ret;
+ GEM_TRACE("\n");
+
intel_runtime_pm_get(dev_priv);
intel_suspend_gt_powersave(dev_priv);
@@ -581,24 +581,58 @@ last_request_on_engine(struct i915_timeline *timeline,
rq = i915_gem_active_raw(&timeline->last_request,
&engine->i915->drm.struct_mutex);
- if (rq && rq->engine == engine)
+ if (rq && rq->engine == engine) {
+ GEM_TRACE("last request for %s on engine %s: %llx:%d\n",
+ timeline->name, engine->name,
+ rq->fence.context, rq->fence.seqno);
return rq;
+ }
return NULL;
}
-static bool engine_has_idle_kernel_context(struct intel_engine_cs *engine)
+static bool engine_has_kernel_context_barrier(struct intel_engine_cs *engine)
{
- struct list_head * const active_rings = &engine->i915->gt.active_rings;
+ struct drm_i915_private *i915 = engine->i915;
+ struct i915_timeline *barrier =
+ to_intel_context(i915->kernel_context, engine)->ring->timeline;
struct intel_ring *ring;
+ bool any_active = false;
- lockdep_assert_held(&engine->i915->drm.struct_mutex);
+ lockdep_assert_held(&i915->drm.struct_mutex);
+ list_for_each_entry(ring, &i915->gt.active_rings, active_link) {
+ struct i915_request *rq;
+
+ rq = last_request_on_engine(ring->timeline, engine);
+ if (!rq)
+ continue;
- list_for_each_entry(ring, active_rings, active_link) {
- if (last_request_on_engine(ring->timeline, engine))
+ if (rq->gem_context == i915->kernel_context)
+ continue;
+
+ /*
+ * Was this request submitted after the previous
+ * switch-to-kernel-context?
+ */
+ if (!i915_timeline_sync_is_later(barrier, &rq->fence)) {
+ GEM_TRACE("%s needs barrier\n", ring->timeline->name);
return false;
+ }
+
+ GEM_TRACE("%s has barrier\n", ring->timeline->name);
+ any_active = true;
}
+ /*
+ * If any other timeline was still active and behind the last barrier,
+ * then our last switch-to-kernel-context must still be queued and
+ * will run last (leaving the engine in the kernel context when it
+ * eventually idles).
+ */
+ if (any_active)
+ return true;
+
+ /* The engine is idle; check that it is idling in the kernel context. */
return intel_engine_has_kernel_context(engine);
}
@@ -607,7 +641,10 @@ int i915_gem_switch_to_kernel_context(struct drm_i915_private *i915)
struct intel_engine_cs *engine;
enum intel_engine_id id;
+ GEM_TRACE("\n");
+
lockdep_assert_held(&i915->drm.struct_mutex);
+ GEM_BUG_ON(!i915->kernel_context);
i915_retire_requests(i915);
@@ -615,9 +652,12 @@ int i915_gem_switch_to_kernel_context(struct drm_i915_private *i915)
struct intel_ring *ring;
struct i915_request *rq;
- if (engine_has_idle_kernel_context(engine))
+ GEM_BUG_ON(!to_intel_context(i915->kernel_context, engine));
+ if (engine_has_kernel_context_barrier(engine))
continue;
+ GEM_TRACE("emit barrier on %s\n", engine->name);
+
rq = i915_request_alloc(engine, i915->kernel_context);
if (IS_ERR(rq))
return PTR_ERR(rq);
@@ -627,10 +667,15 @@ int i915_gem_switch_to_kernel_context(struct drm_i915_private *i915)
struct i915_request *prev;
prev = last_request_on_engine(ring->timeline, engine);
- if (prev)
- i915_sw_fence_await_sw_fence_gfp(&rq->submit,
- &prev->submit,
- I915_FENCE_GFP);
+ if (!prev)
+ continue;
+
+ if (prev->gem_context == i915->kernel_context)
+ continue;
+
+ i915_sw_fence_await_sw_fence_gfp(&rq->submit,
+ &prev->submit,
+ I915_FENCE_GFP);
}
/*
@@ -320,6 +320,7 @@ static void advance_ring(struct i915_request *request)
* is just about to be. Either works, if we miss the last two
* noops - they are safe to be replayed on a reset.
*/
+ GEM_TRACE("marking %s as inactive\n", ring->timeline->name);
tail = READ_ONCE(request->tail);
list_del(&ring->active_link);
} else {
@@ -1095,8 +1096,10 @@ void __i915_request_add(struct i915_request *request, bool flush_caches)
i915_gem_active_set(&timeline->last_request, request);
list_add_tail(&request->ring_link, &ring->request_list);
- if (list_is_first(&request->ring_link, &ring->request_list))
+ if (list_is_first(&request->ring_link, &ring->request_list)) {
+ GEM_TRACE("marking %s as active\n", ring->timeline->name);
list_add(&ring->active_link, &request->i915->gt.active_rings);
+ }
request->emitted_jiffies = jiffies;
/*
We were not very carefully checking to see if an older request on the engine was an earlier switch-to-kernel-context before deciding to emit a new switch. The end result would be that we could get into a permanent loop of trying to emit a new request to perform the switch simply to flush the existing switch. What we need is a means of tracking the completion of each timeline versus the kernel context, that is to detect if a more recent request has been submitted that would result in a switch away from the kernel context. To realise this, we need only to look in our syncmap on the kernel context and check that we have synchronized against all active rings. v2: Since all ringbuffer clients currently share the same timeline, we do have to use the gem_context to distinguish clients. As a bonus, include all the tracing used to debug the death inside suspend. Reported-by: Mika Kuoppala <mika.kuoppala@intel.com> Fixes: a89d1f921c15 ("drm/i915: Split i915_gem_timeline into individual timelines") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuoppala@intel.com> --- drivers/gpu/drm/i915/i915_gem.c | 7 +++ drivers/gpu/drm/i915/i915_gem_context.c | 67 +++++++++++++++++++++---- drivers/gpu/drm/i915/i915_request.c | 5 +- 3 files changed, 67 insertions(+), 12 deletions(-)