PCI/LINK: Deduplicate bandwidth reports for multi-function devices

If a multi-function device's bandwidth is already limited when it is
enumerated, a message is logged only for function 0.  By contrast, when
downtraining occurs after enumeration, a message is logged for all
functions.  That's because the former uses pcie_report_downtraining(),
whereas the latter uses __pcie_print_link_status() (which doesn't filter
functions != 0).  I am seeing this happen on a MacBookPro9,1 with a GPU
(function 0) and an integrated HDA controller (function 1).

Avoid this incongruence by calling pcie_report_downtraining() in both
cases.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Alexandru Gagniuc <alex.gagniuc@dellteam.com>

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

@@ -76,7 +76,7 @@ static irqreturn_t pcie_bw_notification_handler(int irq, void *context)
 	 */
 	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);
 
 	return IRQ_HANDLED;

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;