drm/i915: Queue hangcheck when irqs are disabled

Ensure that the hangcheck is queued even in the absence of interrupts.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170123093724.18592-1-chris@chris-wilson.co.uk
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>

drivers/gpu/drm/i915/intel_breadcrumbs.c

@@ -127,6 +127,7 @@ static void __intel_breadcrumbs_enable_irq(struct intel_breadcrumbs *b)
 	if (!b->irq_enabled ||
 	    test_bit(engine->id, &i915->gpu_error.missed_irq_rings)) {
 		mod_timer(&b->fake_irq, jiffies + 1);
+		i915_queue_hangcheck(i915);
 	} else {
 		/* Ensure we never sleep indefinitely */
 		GEM_BUG_ON(!time_after(b->timeout, jiffies));