Merge tag 'pci-v5.1-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI fixes from Bjorn Helgaas:
 "PCI fixes:

   - Clear level-triggered interrupts for the bandwidth notification
     supported added for v5.1 (Alexandru Gagniuc)

   - Clear bandwidth notification interrupts before enabling them (Lukas
     Wunner)

   - Report post-enumeration bandwidth changes only once for
     multi-function devices (Lukas Wunner)"

* tag 'pci-v5.1-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI/LINK: Deduplicate bandwidth reports for multi-function devices
  PCI/LINK: Clear bandwidth notification interrupt before enabling it
  PCI/LINK: Supply IRQ handler so level-triggered IRQs are acked

drivers/pci/pci.h

@@ -273,6 +273,7 @@ enum pcie_link_width pcie_get_width_cap(struct pci_dev *dev);
 u32 pcie_bandwidth_capable(struct pci_dev *dev, enum pci_bus_speed *speed,
 			   enum pcie_link_width *width);
 void __pcie_print_link_status(struct pci_dev *dev, bool verbose);
+void pcie_report_downtraining(struct pci_dev *dev);
 
 /* Single Root I/O Virtualization */
 struct pci_sriov {

drivers/pci/pcie/bw_notification.c

@@ -30,6 +30,8 @@ static void pcie_enable_link_bandwidth_notification(struct pci_dev *dev)
 {
 	u16 lnk_ctl;
 
+	pcie_capability_write_word(dev, PCI_EXP_LNKSTA, PCI_EXP_LNKSTA_LBMS);
+
 	pcie_capability_read_word(dev, PCI_EXP_LNKCTL, &lnk_ctl);
 	lnk_ctl |= PCI_EXP_LNKCTL_LBMIE;
 	pcie_capability_write_word(dev, PCI_EXP_LNKCTL, lnk_ctl);
@@ -44,11 +46,10 @@ static void pcie_disable_link_bandwidth_notification(struct pci_dev *dev)
 	pcie_capability_write_word(dev, PCI_EXP_LNKCTL, lnk_ctl);
 }
 
-static irqreturn_t pcie_bw_notification_handler(int irq, void *context)
+static irqreturn_t pcie_bw_notification_irq(int irq, void *context)
 {
 	struct pcie_device *srv = context;
 	struct pci_dev *port = srv->port;
-	struct pci_dev *dev;
 	u16 link_status, events;
 	int ret;
 
@@ -58,17 +59,26 @@ static irqreturn_t pcie_bw_notification_handler(int irq, void *context)
 	if (ret != PCIBIOS_SUCCESSFUL || !events)
 		return IRQ_NONE;
 
+	pcie_capability_write_word(port, PCI_EXP_LNKSTA, events);
+	pcie_update_link_speed(port->subordinate, link_status);
+	return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t pcie_bw_notification_handler(int irq, void *context)
+{
+	struct pcie_device *srv = context;
+	struct pci_dev *port = srv->port;
+	struct pci_dev *dev;
+
 	/*
 	 * Print status from downstream devices, not this root port or
 	 * downstream switch port.
 	 */
 	down_read(&pci_bus_sem);
 	list_for_each_entry(dev, &port->subordinate->devices, bus_list)
-		__pcie_print_link_status(dev, false);
+		pcie_report_downtraining(dev);
 	up_read(&pci_bus_sem);
 
-	pcie_update_link_speed(port->subordinate, link_status);
-	pcie_capability_write_word(port, PCI_EXP_LNKSTA, events);
 	return IRQ_HANDLED;
 }
 
@@ -80,7 +90,8 @@ static int pcie_bandwidth_notification_probe(struct pcie_device *srv)
 	if (!pcie_link_bandwidth_notification_supported(srv->port))
 		return -ENODEV;
 
-	ret = request_threaded_irq(srv->irq, NULL, pcie_bw_notification_handler,
+	ret = request_threaded_irq(srv->irq, pcie_bw_notification_irq,
+				   pcie_bw_notification_handler,
 				   IRQF_SHARED, "PCIe BW notif", srv);
 	if (ret)
 		return ret;

drivers/pci/probe.c

@@ -2388,7 +2388,7 @@ static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn)
 	return dev;
 }
 
-static void pcie_report_downtraining(struct pci_dev *dev)
+void pcie_report_downtraining(struct pci_dev *dev)
 {
 	if (!pci_is_pcie(dev))
 		return;