drm/i915: Include interesting seqno in the missed breadcrumb debug

Knowing the neighbouring seqno (current on hw, last submitted to hw)
provide some useful breadcrumbs to the debug log.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170423170619.7156-4-chris@chris-wilson.co.uk
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>

drivers/gpu/drm/i915/intel_breadcrumbs.c

@@ -64,10 +64,12 @@ static unsigned long wait_timeout(void)
 
 static noinline void missed_breadcrumb(struct intel_engine_cs *engine)
 {
-	DRM_DEBUG_DRIVER("%s missed breadcrumb at %pF, irq posted? %s\n",
+	DRM_DEBUG_DRIVER("%s missed breadcrumb at %pF, irq posted? %s, current seqno=%x, last=%x\n",
 			 engine->name, __builtin_return_address(0),
 			 yesno(test_bit(ENGINE_IRQ_BREADCRUMB,
-					&engine->irq_posted)));
+					&engine->irq_posted)),
+			 intel_engine_get_seqno(engine),
+			 intel_engine_last_submit(engine));
 
 	set_bit(engine->id, &engine->i915->gpu_error.missed_irq_rings);
 }