From 33ba90aa4d4432b884fc0ed57ba9dc12eb8fa288 Mon Sep 17 00:00:00 2001
From: Jan Glauber <jglauber@cavium.com>
Date: Fri, 8 Sep 2017 10:10:33 +0200
Subject: [PATCH] PCI: Avoid slot reset if bridge itself is broken
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>
---
drivers/pci/pci.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 74f1c57ab93b6..3e0557bb02c8a 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4424,6 +4424,10 @@ 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;