+/**
+ * artop_6210_qc_defer - implement serialization
+ * @qc: command
+ *
+ * Issue commands per host on this chip.
+ */
+
+static int artop6210_qc_defer(struct ata_queued_cmd *qc)
+{
+ struct ata_host *host = qc->ap->host;
+ struct ata_port *alt = host->ports[1 ^ qc->ap->port_no];
+ int rc;
+
+ /* First apply the usual rules */
+ rc = ata_std_qc_defer(qc);
+ if (rc != 0)
+ return rc;
+
+ /* Now apply serialization rules. Only allow a command if the
+ other channel state machine is idle */
+ if (alt && alt->qc_active)
+ return ATA_DEFER_PORT;
+ return 0;
+}
+