diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 2222635..15863a4 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -309,7 +309,8 @@ ata_scsi_activity_show(struct device *dev, struct device_attribute *attr,
 	struct ata_port *ap = ata_shost_to_port(sdev->host);
 	struct ata_device *atadev = ata_scsi_find_dev(ap, sdev);
 
-	if (ap->ops->sw_activity_show && (ap->flags & ATA_FLAG_SW_ACTIVITY))
+	if (atadev && ap->ops->sw_activity_show &&
+	    (ap->flags & ATA_FLAG_SW_ACTIVITY))
 		return ap->ops->sw_activity_show(atadev, buf);
 	return -EINVAL;
 }
@@ -324,7 +325,8 @@ ata_scsi_activity_store(struct device *dev, struct device_attribute *attr,
 	enum sw_activity val;
 	int rc;
 
-	if (ap->ops->sw_activity_store && (ap->flags & ATA_FLAG_SW_ACTIVITY)) {
+	if (atadev && ap->ops->sw_activity_store &&
+	    (ap->flags & ATA_FLAG_SW_ACTIVITY)) {
 		val = simple_strtoul(buf, NULL, 0);
 		switch (val) {
 		case OFF: case BLINK_ON: case BLINK_OFF: