--- zzzz-none-000/linux-3.10.107/arch/x86/pci/irq.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/arch/x86/pci/irq.c	2021-02-04 17:41:59.000000000 +0000
@@ -26,6 +26,7 @@
 static struct irq_routing_table *pirq_table;
 
 static int pirq_enable_irq(struct pci_dev *dev);
+static void pirq_disable_irq(struct pci_dev *dev);
 
 /*
  * Never use: 0, 1, 2 (timer, keyboard, and cascade)
@@ -53,7 +54,7 @@
 };
 
 int (*pcibios_enable_irq)(struct pci_dev *dev) = pirq_enable_irq;
-void (*pcibios_disable_irq)(struct pci_dev *dev) = NULL;
+void (*pcibios_disable_irq)(struct pci_dev *dev) = pirq_disable_irq;
 
 /*
  *  Check passed address for the PCI IRQ Routing Table signature
@@ -136,32 +137,29 @@
 		busmap[e->bus] = 1;
 	}
 	for (i = 1; i < 256; i++) {
-		int node;
 		if (!busmap[i] || pci_find_bus(0, i))
 			continue;
-		node = get_mp_bus_to_node(i);
-		if (pci_scan_bus_on_node(i, &pci_root_ops, node))
-			printk(KERN_INFO "PCI: Discovered primary peer "
-			       "bus %02x [IRQ]\n", i);
+		pcibios_scan_root(i);
 	}
 	pcibios_last_bus = -1;
 }
 
 /*
  *  Code for querying and setting of IRQ routes on various interrupt routers.
+ *  PIC Edge/Level Control Registers (ELCR) 0x4d0 & 0x4d1.
  */
 
-void eisa_set_level_irq(unsigned int irq)
+void elcr_set_level_irq(unsigned int irq)
 {
 	unsigned char mask = 1 << (irq & 7);
 	unsigned int port = 0x4d0 + (irq >> 3);
 	unsigned char val;
-	static u16 eisa_irq_mask;
+	static u16 elcr_irq_mask;
 
-	if (irq >= 16 || (1 << irq) & eisa_irq_mask)
+	if (irq >= 16 || (1 << irq) & elcr_irq_mask)
 		return;
 
-	eisa_irq_mask |= (1 << irq);
+	elcr_irq_mask |= (1 << irq);
 	printk(KERN_DEBUG "PCI: setting IRQ %u as level-triggered\n", irq);
 	val = inb(port);
 	if (!(val & mask)) {
@@ -968,11 +966,11 @@
 	} else if (r->get && (irq = r->get(pirq_router_dev, dev, pirq)) && \
 	((!(pci_probe & PCI_USE_PIRQ_MASK)) || ((1 << irq) & mask))) {
 		msg = "found";
-		eisa_set_level_irq(irq);
+		elcr_set_level_irq(irq);
 	} else if (newirq && r->set &&
 		(dev->class >> 8) != PCI_CLASS_DISPLAY_VGA) {
 		if (r->set(pirq_router_dev, dev, pirq, newirq)) {
-			eisa_set_level_irq(newirq);
+			elcr_set_level_irq(newirq);
 			msg = "assigned";
 			irq = newirq;
 		}
@@ -1190,7 +1188,7 @@
 
 static int pirq_enable_irq(struct pci_dev *dev)
 {
-	u8 pin;
+	u8 pin = 0;
 
 	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
 	if (pin && !pcibios_lookup_irq(dev, 1)) {
@@ -1203,11 +1201,12 @@
 #ifdef CONFIG_X86_IO_APIC
 			struct pci_dev *temp_dev;
 			int irq;
-			struct io_apic_irq_attr irq_attr;
+
+			if (dev->irq_managed && dev->irq > 0)
+				return 0;
 
 			irq = IO_APIC_get_PCI_irq_vector(dev->bus->number,
-						PCI_SLOT(dev->devfn),
-						pin - 1, &irq_attr);
+						PCI_SLOT(dev->devfn), pin - 1);
 			/*
 			 * Busses behind bridges are typically not listed in the MP-table.
 			 * In this case we have to look up the IRQ based on the parent bus,
@@ -1221,7 +1220,7 @@
 				pin = pci_swizzle_interrupt_pin(dev, pin);
 				irq = IO_APIC_get_PCI_irq_vector(bridge->bus->number,
 						PCI_SLOT(bridge->devfn),
-						pin - 1, &irq_attr);
+						pin - 1);
 				if (irq >= 0)
 					dev_warn(&dev->dev, "using bridge %s "
 						 "INT %c to get IRQ %d\n",
@@ -1231,8 +1230,7 @@
 			}
 			dev = temp_dev;
 			if (irq >= 0) {
-				io_apic_set_pci_routing(&dev->dev, irq,
-							 &irq_attr);
+				dev->irq_managed = 1;
 				dev->irq = irq;
 				dev_info(&dev->dev, "PCI->APIC IRQ transform: "
 					 "INT %c -> IRQ %d\n", 'A' + pin - 1, irq);
@@ -1258,3 +1256,25 @@
 	}
 	return 0;
 }
+
+bool mp_should_keep_irq(struct device *dev)
+{
+	if (dev->power.is_prepared)
+		return true;
+#ifdef CONFIG_PM
+	if (dev->power.runtime_status == RPM_SUSPENDING)
+		return true;
+#endif
+
+	return false;
+}
+
+static void pirq_disable_irq(struct pci_dev *dev)
+{
+	if (io_apic_assign_pci_irqs && !mp_should_keep_irq(&dev->dev) &&
+	    dev->irq_managed && dev->irq) {
+		mp_unmap_irq(dev->irq);
+		dev->irq = 0;
+		dev->irq_managed = 0;
+	}
+}