From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Wed, 27 Jun 2018 21:13:02 +0100
Subject: drm/i915: Only trigger missed-seqno checking next to boundary
Git-commit: 69dc4d003e3b7c262fd5fea3f25852e853eb6d4f
Patch-mainline: v4.19-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

If we have more interrupts pending (because we know there are more
breadcrumb signals before the completion), then we do not need to
trigger an irq_seqno_barrier or even wakeup the task on this interrupt
as there will be another. To allow some margin of error (we are trying
to work around incoherent seqno after all), we wakeup the breadcrumb
before the target as well as on the target.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180627201304.15817-2-chris@chris-wilson.co.uk

Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/i915/i915_irq.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1191,7 +1191,8 @@ static void notify_ring(struct intel_eng
 
 			tsk = wait->tsk;
 		} else {
-			if (engine->irq_seqno_barrier) {
+			if (engine->irq_seqno_barrier &&
+			    i915_seqno_passed(seqno, wait->seqno - 1)) {
 				set_bit(ENGINE_IRQ_BREADCRUMB,
 					&engine->irq_posted);
 				tsk = wait->tsk;