From 15d87efda9abbd0ed447dc54efceb8089c440cf6 Mon Sep 17 00:00:00 2001
From: Jan Glauber <jglauber@cavium.com>
Date: Fri, 8 Sep 2017 10:10:33 +0200
Subject: [PATCH 02/14] PCI: Avoid slot reset if bridge itself is broken

Git-commit: 33ba90aa4d4432b884fc0ed57ba9dc12eb8fa288
Patch-mainline: v4.15-rc1
References: bsc#1084918

When checking to see if a PCI slot can safely be reset, we previously
checked to see if any of the children had their PCI_DEV_FLAGS_NO_BUS_RESET
flag set.

Some PCIe root port bridges do not behave well after a slot reset, and may
cause the device in the slot to become unusable.

Add a check for PCI_DEV_FLAGS_NO_BUS_RESET being set in the bridge device
to prevent the slot from being reset.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>
---
 drivers/pci/pci.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 0bd0563be99e..751ea587154b 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4423,6 +4423,10 @@ static bool pci_slot_resetable(struct pci_slot *slot)
 {
 	struct pci_dev *dev;
 
+	if (slot->bus->self &&
+	    (slot->bus->self->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET))
+		return false;
+
 	list_for_each_entry(dev, &slot->bus->devices, bus_list) {
 		if (!dev->slot || dev->slot != slot)
 			continue;
-- 
2.11.0