diff --git a/qla2x00t-32gbit/Makefile_in-tree b/qla2x00t-32gbit/Makefile_in-tree
index f86fa5a0b..2e7619677 100644
--- a/qla2x00t-32gbit/Makefile_in-tree
+++ b/qla2x00t-32gbit/Makefile_in-tree
@@ -7,4 +7,4 @@ obj-$(CONFIG_SCSI_QLA_FC) += qla2xxx.o
 obj-$(CONFIG_TCM_QLA2XXX) += tcm_qla2xxx.o
 
 ccflags-y += -I$(src)/../../../include/scst/
-ccflags-y += $(call cc-option,-Wno-format-truncation)
+ccflags-y += $(call cc-option,-Wno-stringop-truncation)
diff --git a/qla2x00t-32gbit/qla2x00-target/qla_tgt.c b/qla2x00t-32gbit/qla2x00-target/qla_tgt.c
index a6b010830..0dd5b619b 100644
--- a/qla2x00t-32gbit/qla2x00-target/qla_tgt.c
+++ b/qla2x00t-32gbit/qla2x00-target/qla_tgt.c
@@ -45,10 +45,6 @@
 #include "qla_def.h"
 #include "scst_qla2xxx.h"
 
-extern struct mutex qla_tgt_mutex;
-extern struct list_head qla_tgt_glist;
-
-
 size_t qlt_add_vtarget(u64 port_name, u64 node_name, u64 parent_host)
 {
 	struct Scsi_Host *shost = NULL;
diff --git a/qla2x00t-32gbit/qla2x00-target/scst_qla2xxx.c b/qla2x00t-32gbit/qla2x00-target/scst_qla2xxx.c
index 964d3673c..76233876e 100644
--- a/qla2x00t-32gbit/qla2x00-target/scst_qla2xxx.c
+++ b/qla2x00t-32gbit/qla2x00-target/scst_qla2xxx.c
@@ -1528,7 +1528,6 @@ static int sqa_init_scst_tgt(struct scsi_qla_host *vha)
 	return res;
 }
 
-extern struct list_head qla_tgt_glist;
 static void sqa_get_target_list(void)
 {
 	struct qla_tgt *tgt;
diff --git a/qla2x00t-32gbit/qla_isr.c b/qla2x00t-32gbit/qla_isr.c
index a2381156a..7099ede9d 100644
--- a/qla2x00t-32gbit/qla_isr.c
+++ b/qla2x00t-32gbit/qla_isr.c
@@ -3423,21 +3423,15 @@ qla2xxx_msix_rsp_q(int irq, void *dev_id)
 
 /* <linux/pci.h> */
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 8, 0) &&	\
-	(!defined(RHEL_MAJOR) || RHEL_MAJOR -0 < 7)
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0) ||	\
+	(defined(RHEL_MAJOR) && RHEL_MAJOR -0 >= 7)
 /*
  * See also commit aff171641d18 ("PCI: Provide sensible IRQ vector alloc/free
  * routines") # v4.8.
  */
-/**
- * pci_irq_vector - return Linux IRQ number of a device vector
- * @dev: PCI device to operate on
- * @nr: device-relative interrupt vector index (0-based).
- */
-static inline int pci_irq_vector(struct pci_dev *dev, unsigned int nr)
-{
-	return dev->irq + nr;
-}
+#define HAVE_PCI_IRQ_VECTOR 1
+#else
+#define HAVE_PCI_IRQ_VECTOR 0
 #endif
 
 struct qla_init_msix_entry {
@@ -3457,6 +3451,28 @@ static const struct qla_init_msix_entry qla82xx_msix_entries[] = {
 	{ "qla2xxx (rsp_q)", qla82xx_msix_rsp_q },
 };
 
+#if !HAVE_PCI_IRQ_VECTOR
+static void
+qla24xx_disable_msix(struct qla_hw_data *ha)
+{
+	int i;
+	struct qla_msix_entry *qentry;
+	scsi_qla_host_t *vha = pci_get_drvdata(ha->pdev);
+
+	for (i = 0; i < ha->msix_count; i++) {
+		qentry = &ha->msix_entries[i];
+		if (qentry->have_irq)
+			free_irq(qentry->vector, qentry->handle);
+	}
+	pci_disable_msix(ha->pdev);
+	kfree(ha->msix_entries);
+	ha->msix_entries = NULL;
+	ha->flags.msix_enabled = 0;
+	ql_dbg(ql_dbg_init, vha, 0x0042,
+	    "Disabled the MSI.\n");
+}
+#endif
+
 static int
 qla24xx_enable_msix(struct qla_hw_data *ha, struct rsp_que *rsp)
 {
@@ -3478,7 +3494,9 @@ qla24xx_enable_msix(struct qla_hw_data *ha, struct rsp_que *rsp)
 
 	for (i = 0; i < ha->msix_count; i++)
 		entries[i].entry = i;
-#elif LINUX_VERSION_CODE < KERNEL_VERSION(4, 10, 0)
+#endif
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 10, 0)
 	if (QLA_TGT_MODE_ENABLED() && (ql2xenablemsix != 0) &&
 	    IS_ATIO_MSIX_CAPABLE(ha)) {
 		min_vecs++;
@@ -3495,6 +3513,8 @@ qla24xx_enable_msix(struct qla_hw_data *ha, struct rsp_que *rsp)
 	}
 #endif
 
+	WARN_ON_ONCE(min_vecs > ha->msix_count);
+
 #if LINUX_VERSION_CODE < KERNEL_VERSION(3, 14, 0) && !defined(RHEL_MAJOR)
 	ret = pci_enable_msix(ha->pdev, entries, ha->msix_count);
 	if (ret) {
@@ -3515,7 +3535,8 @@ msix_failed:
 			    ha->msix_count, ret);
 			goto msix_out;
 		}
-		ha->max_rsp_queues = ha->msix_count - 1;
+	} else {
+		ret = ha->msix_count;
 	}
 #elif LINUX_VERSION_CODE < KERNEL_VERSION(4, 8, 0)
 	ret = pci_enable_msix_range(ha->pdev,
@@ -3534,10 +3555,6 @@ msix_failed:
 		    &desc);
 #endif
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 8, 0)
-	kfree(entries);
-#endif
-
 	if (ret < 0) {
 		ql_log(ql_log_fatal, vha, 0x00c7,
 		    "MSI-X: Failed to enable support, "
@@ -3583,8 +3600,13 @@ msix_failed:
 
 	for (i = 0; i < ha->msix_count; i++) {
 		qentry = &ha->msix_entries[i];
+#if HAVE_PCI_IRQ_VECTOR
 		qentry->vector = pci_irq_vector(ha->pdev, i);
 		qentry->entry = i;
+#else
+		qentry->vector = entries[i].vector;
+		qentry->entry = entries[i].entry;
+#endif
 		qentry->have_irq = 0;
 		qentry->in_use = 0;
 		qentry->handle = NULL;
@@ -3659,6 +3681,9 @@ msix_register_fail:
 	    ha->mqiobase, ha->max_rsp_queues, ha->max_req_queues);
 
 msix_out:
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 8, 0)
+	kfree(entries);
+#endif
 	return ret;
 }
 
@@ -3772,6 +3797,7 @@ qla2x00_free_irqs(scsi_qla_host_t *vha)
 		goto free_irqs;
 	rsp = ha->rsp_q_map[0];
 
+#if HAVE_PCI_IRQ_VECTOR
 	if (ha->flags.msix_enabled) {
 		struct qla_msix_entry *qentry;
 		int i;
@@ -3791,6 +3817,15 @@ qla2x00_free_irqs(scsi_qla_host_t *vha)
 	} else {
 		free_irq(pci_irq_vector(ha->pdev, 0), rsp);
 	}
+#else
+	if (ha->flags.msix_enabled)
+		qla24xx_disable_msix(ha);
+	else if (ha->flags.msi_enabled) {
+		free_irq(ha->pdev->irq, rsp);
+		pci_disable_msi(ha->pdev);
+	} else
+		free_irq(ha->pdev->irq, rsp);
+#endif
 
 free_irqs:
 #if LINUX_VERSION_CODE < KERNEL_VERSION(4, 8, 0)
diff --git a/qla2x00t-32gbit/qla_target.h b/qla2x00t-32gbit/qla_target.h
index 874e4b24f..55d056e03 100644
--- a/qla2x00t-32gbit/qla_target.h
+++ b/qla2x00t-32gbit/qla_target.h
@@ -1043,6 +1043,9 @@ struct qla_tgt_prm {
 
 
 extern struct qla_tgt_data qla_target;
+extern struct mutex qla_tgt_mutex;
+extern struct list_head qla_tgt_glist;
+
 
 /*
  * Function prototypes for qla_target.c logic used by qla2xxx LLD code.
diff --git a/scst/include/backport.h b/scst/include/backport.h
index 6e9b92cd9..6b2273ced 100644
--- a/scst/include/backport.h
+++ b/scst/include/backport.h
@@ -815,6 +815,21 @@ static inline long get_user_pages_backport(unsigned long start,
 #define get_user_pages get_user_pages_backport
 #endif
 
+/* <linux/mempoool.h> */
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 3, 0)
+/*
+ * See also commit 4e3ca3e033d1 ("mm/mempool: allow NULL `pool' pointer in
+ * mempool_destroy()") # v4.3.
+ */
+static inline void mempool_destroy_backport(mempool_t *pool)
+{
+	if (pool)
+		mempool_destroy(pool);
+}
+
+#define mempool_destroy mempool_destroy_backport
+#endif
+
 /* <linux/mm.h> */
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(4, 12, 0) &&	\