diff --git a/qla2x00t/qla_attr.c b/qla2x00t/qla_attr.c
index df4b0c7c1..99ca9e2af 100644
--- a/qla2x00t/qla_attr.c
+++ b/qla2x00t/qla_attr.c
@@ -419,7 +419,7 @@ qla2x00_update_portdb(struct device *dev,
 		printk(KERN_INFO "Reconfiguring fabric on %ld\n",
 			vha->host_no);
 		qla2x00_configure_fabric(vha);
-		/* fall through */
+		fallthrough;
 
 	default:
 		printk(KERN_INFO "Resyncing loop on %ld\n",
diff --git a/qla2x00t/qla_bsg.c b/qla2x00t/qla_bsg.c
index 3239e77a7..284747c54 100644
--- a/qla2x00t/qla_bsg.c
+++ b/qla2x00t/qla_bsg.c
@@ -308,7 +308,7 @@ qla2x00_process_els(struct bsg_job *bsg_job)
 	srb_t *sp;
 	const char *type;
 	int req_sg_cnt, rsp_sg_cnt;
-	int rval =  (DRIVER_ERROR << 16);
+	int rval = DID_ERROR << 16;
 	uint16_t nextlid = 0;
 
 #ifdef __COVERITY__
@@ -495,7 +495,7 @@ qla2x00_process_ct(struct bsg_job *bsg_job)
 	struct fc_bsg_request *bsg_request = bsg_job->request;
 	scsi_qla_host_t *vha = shost_priv(host);
 	struct qla_hw_data *ha = vha->hw;
-	int rval = (DRIVER_ERROR << 16);
+	int rval = DID_ERROR << 16;
 	int req_sg_cnt, rsp_sg_cnt;
 	uint16_t loop_id;
 	struct fc_port *fcport;
diff --git a/qla2x00t/qla_isr.c b/qla2x00t/qla_isr.c
index bc5b4bf0e..f591b0efa 100644
--- a/qla2x00t/qla_isr.c
+++ b/qla2x00t/qla_isr.c
@@ -885,7 +885,7 @@ skip_rio:
 	case MBA_CHG_IN_CONNECTION:	/* Change in connection mode */
 		if (IS_QLA2100(ha))
 			break;
-		/* fall through */
+		fallthrough;
 	case MBA_RESET:			/* Reset */
 	case MBA_SYSTEM_ERR:		/* System Error */
 	case MBA_REQ_TRANSFER_ERR:	/* Request Transfer Error */
@@ -1667,31 +1667,22 @@ qla2x00_handle_dif_error(srb_t *sp, struct sts_entry_24xx *sts24)
 
 	/* check guard */
 	if (e_guard != a_guard) {
-		scsi_build_sense_buffer(1, cmd->sense_buffer, ILLEGAL_REQUEST,
-		    0x10, 0x1);
-		set_driver_byte(cmd, DRIVER_SENSE);
+		scsi_build_sense(cmd, 1, ILLEGAL_REQUEST, 0x10, 0x1);
 		set_host_byte(cmd, DID_ABORT);
-		cmd->result |= SAM_STAT_CHECK_CONDITION << 1;
 		return 1;
 	}
 
 	/* check ref tag */
 	if (e_ref_tag != a_ref_tag) {
-		scsi_build_sense_buffer(1, cmd->sense_buffer, ILLEGAL_REQUEST,
-		    0x10, 0x3);
-		set_driver_byte(cmd, DRIVER_SENSE);
+		scsi_build_sense(cmd, 1, ILLEGAL_REQUEST, 0x10, 0x3);
 		set_host_byte(cmd, DID_ABORT);
-		cmd->result |= SAM_STAT_CHECK_CONDITION << 1;
 		return 1;
 	}
 
 	/* check appl tag */
 	if (e_app_tag != a_app_tag) {
-		scsi_build_sense_buffer(1, cmd->sense_buffer, ILLEGAL_REQUEST,
-		    0x10, 0x2);
-		set_driver_byte(cmd, DRIVER_SENSE);
+		scsi_build_sense(cmd, 1, ILLEGAL_REQUEST, 0x10, 0x2);
 		set_host_byte(cmd, DID_ABORT);
-		cmd->result |= SAM_STAT_CHECK_CONDITION << 1;
 		return 1;
 	}
 
@@ -2251,7 +2242,7 @@ void qla24xx_process_response_queue(struct scsi_qla_host *vha,
 		case ABTS_RECV_24XX:
 			/* ensure that the ATIO queue is empty */
 			qla24xx_process_atio_queue(vha);
-			/* fall through */
+			fallthrough;
 		case ABTS_RESP_24XX:
 		case CTIO_TYPE7:
 		case NOTIFY_ACK_TYPE:
diff --git a/qla2x00t/qla_sup.c b/qla2x00t/qla_sup.c
index 18b745ee1..cadecdb75 100644
--- a/qla2x00t/qla_sup.c
+++ b/qla2x00t/qla_sup.c
@@ -2329,8 +2329,7 @@ qla2x00_write_optrom_data(struct scsi_qla_host *vha, uint8_t *buf,
 				sec_mask = 0x10000;
 				break;
 			}
-			/* Fall through... */
-
+			fallthrough;
 		case 0x1f: /* Atmel flash. */
 			/* 512k sector size. */
 			if (flash_id == 0x13) {
@@ -2338,8 +2337,7 @@ qla2x00_write_optrom_data(struct scsi_qla_host *vha, uint8_t *buf,
 				sec_mask =   0x80000000;
 				break;
 			}
-			/* Fall through... */
-
+			fallthrough;
 		case 0x01: /* AMD flash. */
 			if (flash_id == 0x38 || flash_id == 0x40 ||
 			    flash_id == 0x4f) {
@@ -2371,7 +2369,7 @@ qla2x00_write_optrom_data(struct scsi_qla_host *vha, uint8_t *buf,
 				sec_mask = 0x1e000;
 				break;
 			}
-			/* Fall through... */
+			fallthrough;
 		default:
 			/* Default to 16 kb sector size. */
 			rest_addr = 0x3fff;
diff --git a/scst/include/backport.h b/scst/include/backport.h
index a8850f665..353d975be 100644
--- a/scst/include/backport.h
+++ b/scst/include/backport.h
@@ -2145,6 +2145,41 @@ static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
 }
 #endif
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 14, 0)
+/*
+ * See also commit f2b1e9c6f867 ("scsi: core: Introduce scsi_build_sense()";
+ * v5.14-rc1).
+ */
+static inline void scsi_build_sense(struct scsi_cmnd *scmd, int desc,
+                            u8 key, u8 asc, u8 ascq)
+{
+	scsi_build_sense_buffer(desc, scmd->sense_buffer, key, asc, ascq);
+	scmd->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
+}
+#endif
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 15, 0)
+/*
+ * See also 51f3a4788928 ("scsi: core: Introduce the scsi_cmd_to_rq()
+ * function").
+ */
+static inline struct request *scsi_cmd_to_rq(struct scsi_cmnd *scmd)
+{
+	return blk_mq_rq_from_pdu(scmd);
+}
+
+/*
+ * See also commit 7ba46799d346 ("scsi: core: Add scsi_prot_ref_tag()
+ * helper").
+ */
+static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
+{
+	struct request *rq = blk_mq_rq_from_pdu(scmd);
+
+	return t10_pi_ref_tag(rq);
+}
+#endif
+
 /* <scsi/scsi_request.h> */
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(4, 11, 0)
diff --git a/scst_local/scst_local.c b/scst_local/scst_local.c
index 34d9727e8..0eda086a2 100644
--- a/scst_local/scst_local.c
+++ b/scst_local/scst_local.c
@@ -1653,7 +1653,14 @@ out:
 	return ret;
 }
 
-static int scst_local_driver_remove(struct device *dev)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 15, 0)
+/* See also commit fc7a6209d571 ("bus: Make remove callback return void") */
+#define DRIVER_REMOVE_RET int
+#else
+#define DRIVER_REMOVE_RET void
+#endif
+
+static DRIVER_REMOVE_RET scst_local_driver_remove(struct device *dev)
 {
 	struct scst_local_sess *sess;
 	struct Scsi_Host *shost = NULL;
@@ -1670,7 +1677,7 @@ static int scst_local_driver_remove(struct device *dev)
 	scsi_host_put(shost);
 
 	TRACE_EXIT();
-	return 0;
+	return (DRIVER_REMOVE_RET)0;
 }
 
 static int scst_local_bus_match(struct device *dev,