From 9cd90018ebd5b4f484300f2a5af804317d3428a1 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Tue, 27 Jun 2017 16:25:10 +0100
Subject: [PATCH] drm/i915: Cancel pending execlists irq handler upon idling
Git-commit: 9cd90018ebd5b4f484300f2a5af804317d3428a1
Patch-mainline: v4.14-rc1
References: FATE#322643 bsc#1055900

Due to the slight asynchronicity in handling the execlists interrupts
(i.e. we defer the work to a handler that may consume more than one
interrupt event), when the engine is idle we may still have an irq
tasklet queued (especially when it has been deferred to a ksoftirqd).
At the beginning of the tasklet, we assert that we do hold a device
wakeref for the access we are about to perform. This assumes that when
we idle and release the GT wakeref, all execlists work has been
completed (since the elsp tracking says the hw is idle). However, there
may still be a tasklet queued, so as we mark the engine idle, also
cancel any pending tasklet.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170627152510.28589-1-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/i915/intel_engine_cs.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -1328,6 +1328,7 @@ void intel_engines_mark_idle(struct drm_
 	for_each_engine(engine, i915, id) {
 		intel_engine_disarm_breadcrumbs(engine);
 		i915_gem_batch_pool_fini(&engine->batch_pool);
+		tasklet_kill(&engine->irq_tasklet);
 		engine->no_priolist = false;
 	}
 }