diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 5ab220e..d1803c9 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -3282,9 +3282,9 @@
 {
 	/* send SCSI cdb */
 	DPRINTK("send cdb\n");
-	WARN_ON(ap->cdb_len < 12);
+	WARN_ON(qc->dev->cdb_len < 12);
 
-	ata_data_xfer(ap, qc->cdb, ap->cdb_len, 1);
+	ata_data_xfer(ap, qc->cdb, qc->dev->cdb_len, 1);
 	ata_altstatus(ap); /* flush */
 
 	switch (qc->tf.protocol) {