PCI/ERR: Fix uevent on failure to recover

Upon failure to recover from a PCIe error through AER, DPC or EDR, a
uevent is sent to inform user space about disconnection of the bridge
whose subordinate devices failed to recover.

However the bridge itself is not disconnected.  Instead, a uevent should
be sent for each of the subordinate devices.

Only if the "bridge" happens to be a Root Complex Event Collector or
Integrated Endpoint does it make sense to send a uevent for it (because
there are no subordinate devices).

Right now if there is a mix of subordinate devices with and without
pci_error_handlers, a BEGIN_RECOVERY event is sent for those with
pci_error_handlers but no FAILED_RECOVERY event is ever sent for them
afterwards.  Fix it.

Fixes: 856e1eb ("PCI/AER: Add uevents in AER and EEH error/resume")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org  # v4.16+
Link: https://patch.msgid.link/68fc527a380821b5d861dd554d2ce42cb739591c.1755008151.git.lukas@wunner.de

Author: l1k

drivers/pci/pcie/err.c

@@ -108,6 +108,12 @@ static int report_normal_detected(struct pci_dev *dev, void *data)
 	return report_error_detected(dev, pci_channel_io_normal, data);
 }
 
+static int report_perm_failure_detected(struct pci_dev *dev, void *data)
+{
+	pci_uevent_ers(dev, PCI_ERS_RESULT_DISCONNECT);
+	return 0;
+}
+
 static int report_mmio_enabled(struct pci_dev *dev, void *data)
 {
 	struct pci_driver *pdrv;
@@ -272,7 +278,7 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
 failed:
 	pci_walk_bridge(bridge, pci_pm_runtime_put, NULL);
 
-	pci_uevent_ers(bridge, PCI_ERS_RESULT_DISCONNECT);
+	pci_walk_bridge(bridge, report_perm_failure_detected, NULL);
 
 	pci_info(bridge, "device recovery failed\n");