diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 53380bd72ea4..c70476b34a53 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -41,8 +41,15 @@ config ARM_GIC_V3
 
 config ARM_GIC_V3_ITS
 	bool
+	select GENERIC_MSI_IRQ_DOMAIN
+	default ARM_GIC_V3
+
+config ARM_GIC_V3_ITS_PCI
+	bool
+	depends on ARM_GIC_V3_ITS
 	depends on PCI
 	depends on PCI_MSI
+	default ARM_GIC_V3_ITS
 
 config ARM_NVIC
 	bool
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index dae7282bfdef..d2df34a54d38 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -30,7 +30,8 @@ obj-$(CONFIG_ARM_GIC_PM)		+= irq-gic-pm.o
 obj-$(CONFIG_ARCH_REALVIEW)		+= irq-gic-realview.o
 obj-$(CONFIG_ARM_GIC_V2M)		+= irq-gic-v2m.o
 obj-$(CONFIG_ARM_GIC_V3)		+= irq-gic-v3.o irq-gic-common.o
-obj-$(CONFIG_ARM_GIC_V3_ITS)		+= irq-gic-v3-its.o irq-gic-v3-its-pci-msi.o irq-gic-v3-its-platform-msi.o irq-gic-v4.o
+obj-$(CONFIG_ARM_GIC_V3_ITS)		+= irq-gic-v3-its.o irq-gic-v3-its-platform-msi.o irq-gic-v4.o
+obj-$(CONFIG_ARM_GIC_V3_ITS_PCI)	+= irq-gic-v3-its-pci-msi.o
 obj-$(CONFIG_PARTITION_PERCPU)		+= irq-partition-percpu.o
 obj-$(CONFIG_HISILICON_IRQ_MBIGEN)	+= irq-mbigen.o
 obj-$(CONFIG_ARM_NVIC)			+= irq-nvic.o
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index b54b55597ffb..16fddff38f22 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -1103,18 +1103,18 @@ static void __init gic_populate_ppi_partitions(struct device_node *gic_node)
 	int nr_parts;
 	struct partition_affinity *parts;
 
-	parts_node = of_find_node_by_name(gic_node, "ppi-partitions");
+	parts_node = of_get_child_by_name(gic_node, "ppi-partitions");
 	if (!parts_node)
 		return;
 
 	nr_parts = of_get_child_count(parts_node);
 
 	if (!nr_parts)
-		return;
+		goto out_put_node;
 
 	parts = kzalloc(sizeof(*parts) * nr_parts, GFP_KERNEL);
 	if (WARN_ON(!parts))
-		return;
+		goto out_put_node;
 
 	for_each_child_of_node(parts_node, child_part) {
 		struct partition_affinity *part;
@@ -1181,6 +1181,9 @@ static void __init gic_populate_ppi_partitions(struct device_node *gic_node)
 
 		gic_data.ppi_descs[i] = desc;
 	}
+
+out_put_node:
+	of_node_put(parts_node);
 }
 
 static void __init gic_of_setup_kvm_info(struct device_node *node)
@@ -1521,7 +1524,7 @@ gic_acpi_init(struct acpi_subtable_header *header, const unsigned long end)
 
 	err = gic_validate_dist_version(acpi_data.dist_base);
 	if (err) {
-		pr_err("No distributor detected at @%p, giving up",
+		pr_err("No distributor detected at @%p, giving up\n",
 		       acpi_data.dist_base);
 		goto out_dist_unmap;
 	}
diff --git a/drivers/irqchip/irq-gic-v4.c b/drivers/irqchip/irq-gic-v4.c
index cd0bcc3b7e33..dba9d67cb9c1 100644
--- a/drivers/irqchip/irq-gic-v4.c
+++ b/drivers/irqchip/irq-gic-v4.c
@@ -177,6 +177,7 @@ int its_map_vlpi(int irq, struct its_vlpi_map *map)
 			.map      = map,
 		},
 	};
+	int ret;
 
 	/*
 	 * The host will never see that interrupt firing again, so it
@@ -184,7 +185,11 @@ int its_map_vlpi(int irq, struct its_vlpi_map *map)
 	 */
 	irq_set_status_flags(irq, IRQ_DISABLE_UNLAZY);
 
-	return irq_set_vcpu_affinity(irq, &info);
+	ret = irq_set_vcpu_affinity(irq, &info);
+	if (ret)
+		irq_clear_status_flags(irq, IRQ_DISABLE_UNLAZY);
+
+	return ret;
 }
 
 int its_get_vlpi(int irq, struct its_vlpi_map *map)
diff --git a/drivers/irqchip/irq-s3c24xx.c b/drivers/irqchip/irq-s3c24xx.c
index c25ce5af091a..ec0e6a8cdb75 100644
--- a/drivers/irqchip/irq-s3c24xx.c
+++ b/drivers/irqchip/irq-s3c24xx.c
@@ -156,7 +156,7 @@ static int s3c_irq_type(struct irq_data *data, unsigned int type)
 		irq_set_handler(data->irq, handle_level_irq);
 		break;
 	default:
-		pr_err("No such irq type %d", type);
+		pr_err("No such irq type %d\n", type);
 		return -EINVAL;
 	}
 
@@ -204,7 +204,7 @@ static int s3c_irqext_type_set(void __iomem *gpcon_reg,
 			break;
 
 		default:
-			pr_err("No such irq type %d", type);
+			pr_err("No such irq type %d\n", type);
 			return -EINVAL;
 	}
 
diff --git a/include/linux/irq.h b/include/linux/irq.h
index b01d06db9101..e140f69163b6 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -211,6 +211,7 @@ struct irq_data {
  * IRQD_MANAGED_SHUTDOWN	- Interrupt was shutdown due to empty affinity
  *				  mask. Applies only to affinity managed irqs.
  * IRQD_SINGLE_TARGET		- IRQ allows only a single affinity target
+ * IRQD_DEFAULT_TRIGGER_SET	- Expected trigger already been set
  */
 enum {
 	IRQD_TRIGGER_MASK		= 0xf,
@@ -231,6 +232,7 @@ enum {
 	IRQD_IRQ_STARTED		= (1 << 22),
 	IRQD_MANAGED_SHUTDOWN		= (1 << 23),
 	IRQD_SINGLE_TARGET		= (1 << 24),
+	IRQD_DEFAULT_TRIGGER_SET	= (1 << 25),
 };
 
 #define __irqd_to_state(d) ACCESS_PRIVATE((d)->common, state_use_accessors)
@@ -260,18 +262,25 @@ static inline void irqd_mark_affinity_was_set(struct irq_data *d)
 	__irqd_to_state(d) |= IRQD_AFFINITY_SET;
 }
 
+static inline bool irqd_trigger_type_was_set(struct irq_data *d)
+{
+	return __irqd_to_state(d) & IRQD_DEFAULT_TRIGGER_SET;
+}
+
 static inline u32 irqd_get_trigger_type(struct irq_data *d)
 {
 	return __irqd_to_state(d) & IRQD_TRIGGER_MASK;
 }
 
 /*
- * Must only be called inside irq_chip.irq_set_type() functions.
+ * Must only be called inside irq_chip.irq_set_type() functions or
+ * from the DT/ACPI setup code.
  */
 static inline void irqd_set_trigger_type(struct irq_data *d, u32 type)
 {
 	__irqd_to_state(d) &= ~IRQD_TRIGGER_MASK;
 	__irqd_to_state(d) |= type & IRQD_TRIGGER_MASK;
+	__irqd_to_state(d) |= IRQD_DEFAULT_TRIGGER_SET;
 }
 
 static inline bool irqd_is_level_type(struct irq_data *d)
diff --git a/include/linux/irqchip/arm-gic-v4.h b/include/linux/irqchip/arm-gic-v4.h
index 447da8ca2156..fa683ea5c769 100644
--- a/include/linux/irqchip/arm-gic-v4.h
+++ b/include/linux/irqchip/arm-gic-v4.h
@@ -109,6 +109,7 @@ int its_get_vlpi(int irq, struct its_vlpi_map *map);
 int its_unmap_vlpi(int irq);
 int its_prop_update_vlpi(int irq, u8 config, bool inv);
 
+struct irq_domain_ops;
 int its_init_v4(struct irq_domain *domain, const struct irq_domain_ops *ops);
 
 #endif
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 2ff1c0c82fc9..0f922729bab9 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1246,7 +1246,18 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 		 * set the trigger type must match. Also all must
 		 * agree on ONESHOT.
 		 */
-		unsigned int oldtype = irqd_get_trigger_type(&desc->irq_data);
+		unsigned int oldtype;
+
+		/*
+		 * If nobody did set the configuration before, inherit
+		 * the one provided by the requester.
+		 */
+		if (irqd_trigger_type_was_set(&desc->irq_data)) {
+			oldtype = irqd_get_trigger_type(&desc->irq_data);
+		} else {
+			oldtype = new->flags & IRQF_TRIGGER_MASK;
+			irqd_set_trigger_type(&desc->irq_data, oldtype);
+		}
 
 		if (!((old->flags & new->flags) & IRQF_SHARED) ||
 		    (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||