Commit 93eef7d6 authored Mar 06, 2018 by Chris Wilson

drm/i915: Stop kicking the signaling thread on seqno wraparound

Since commit fd10e2ce ("drm/i915/breadcrumbs: Ignore unsubmitted
signalers"), we cancel the signaler when retiring the request and so
upon wraparound, where we wait for all requests to be retired, we no
longer need to spin waiting for the signaling thread to release its
references to the in-flight requests, and so we can assert that the
signaler is idle.

References: fd10e2ce ("drm/i915/breadcrumbs: Ignore unsubmitted signalers")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180306130143.13312-1-chris@chris-wilson.co.uk

parent 9792e213

drivers/gpu/drm/i915/i915_request.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -220,6 +220,8 @@ static int reset_all_global_seqno(struct drm_i915_private *i915, u32 seqno)
		/* spin until threads are complete */
		while (intel_breadcrumbs_busy(engine))
		cond_resched();

		GEM_BUG_ON(!list_empty(&engine->breadcrumbs.signals));
		}

		/* Check we are idle before we fiddle with hw state! */

+0 −5

Original line number	Diff line number	Diff line
		@@ -889,11 +889,6 @@ bool intel_breadcrumbs_busy(struct intel_engine_cs *engine)
		spin_unlock_irq(&b->irq_lock);
		}

		if (!busy && !list_empty(&b->signals)) {
		wake_up_process(b->signaler);
		busy = true;
		}

		return busy;
		}