+static irqreturn_t vas_irq_handler(int virq, void *data)
+{
+	struct vas_instance *vinst = data;
+
+	pr_devel("VAS %d: virq %d\n", vinst->vas_id, virq);
+
+	return IRQ_HANDLED;
+}

An empty interrupt handler is rather pointless.  It later grows code,
but adding it without that is a bad idea.  Please squash the patches
into sesible chunks.