diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index d3f28b82c97b9f..0e96ed408c71a4 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -1835,6 +1835,9 @@ static unsigned int ata_scsiop_inq_std(struct ata_scsi_args *args, u8 *rbuf)
 		hdr[2] = 0x7; /* claim SPC-5 version compatibility */
 	}
 
+	if (args->dev->flags & ATA_DFLAG_CDL)
+		hdr[2] = 0xd; /* claim SPC-6 version compatibility */
+
 	memcpy(rbuf, hdr, sizeof(hdr));
 	memcpy(&rbuf[8], "ATA     ", 8);
 	ata_id_string(args->id, &rbuf[16], ATA_ID_PROD, 16);
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index d0911bc28663a8..89367c4bf0ef5e 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -613,6 +613,17 @@ void scsi_cdl_check(struct scsi_device *sdev)
 	bool cdl_supported;
 	unsigned char *buf;
 
+	/*
+	 * Support for CDL was defined in SPC-5. Ignore devices reporting an
+	 * lower SPC version. This also avoids problems with old drives choking
+	 * on MAINTENANCE_IN / MI_REPORT_SUPPORTED_OPERATION_CODES with a
+	 * service action specified, as done in scsi_cdl_check_cmd().
+	 */
+	if (sdev->scsi_level < SCSI_SPC_5) {
+		sdev->cdl_supported = 0;
+		return;
+	}
+
 	buf = kmalloc(SCSI_CDL_CHECK_BUF_LEN, GFP_KERNEL);
 	if (!buf) {
 		sdev->cdl_supported = 0;
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 52014b2d39e1c5..eaa972bee6c00e 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -822,7 +822,7 @@ static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
 	 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so
 	 * non-zero LUNs can be scanned.
 	 */
-	sdev->scsi_level = inq_result[2] & 0x07;
+	sdev->scsi_level = inq_result[2] & 0x0f;
 	if (sdev->scsi_level >= 2 ||
 	    (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
 		sdev->scsi_level++;
diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h
index ec093594ba53df..4498f845b11221 100644
--- a/include/scsi/scsi.h
+++ b/include/scsi/scsi.h
@@ -157,6 +157,9 @@ enum scsi_disposition {
 #define SCSI_3          4        /* SPC */
 #define SCSI_SPC_2      5
 #define SCSI_SPC_3      6
+#define SCSI_SPC_4	7
+#define SCSI_SPC_5	8
+#define SCSI_SPC_6	14
 
 /*
  * INQ PERIPHERAL QUALIFIERS