From 4ee056f41807858b2eae263e74ae8b81800c0337 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Wed, 21 Jun 2017 13:48:04 +0100
Subject: [PATCH] drm/i915: Cancel pending execlist tasklet upon wedging
Git-commit: 4ee056f41807858b2eae263e74ae8b81800c0337
Patch-mainline: v4.14-rc1
References: FATE#322643 bsc#1055900

Highly unlikely, but if the stop_machine() did suspend the tasklet, we
want to make sure that when it wakes it finds there is nothing to do.
Otherwise, it will loudly complain that the ELSP port tracking no longer
matches the hardware, and we will be mightly confused.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170621124804.4529-1-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/i915/i915_gem.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3093,6 +3093,13 @@ static void engine_set_wedged(struct int
 		engine->execlist_first = NULL;
 
 		spin_unlock_irqrestore(&engine->timeline->lock, flags);
+
+		/* The port is checked prior to scheduling a tasklet, but
+		 * just in case we have suspended the tasklet to do the
+		 * wedging make sure that when it wakes, it decides there
+		 * is no work to do by clearing the irq_posted bit.
+		 */
+		clear_bit(ENGINE_IRQ_EXECLIST, &engine->irq_posted);
 	}
 }