{
struct amd_iommu *iommu;
+ /*
+ * First check if the device is still attached. It might already
+ * be detached from its domain because the generic
+ * iommu_detach_group code detached it and we try again here in
+ * our alias handling.
+ */
+ if (!dev_data->domain)
+ return;
+
iommu = amd_iommu_rlookup_table[dev_data->devid];
/* decrease reference counters */