PCI: Avoid bus reset if bridge itself is broken
authorDavid Daney <david.daney@cavium.com>
Fri, 8 Sep 2017 08:10:31 +0000 (10:10 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 25 Dec 2017 13:22:14 +0000 (14:22 +0100)
commit8f376337c6379af927e1a44bbe5b311f033ab1ad
tree5dacf1b3500481fb2366ae6e74cbfd37bf9ce101
parent3190a0623c583b1cc29770a4004036c20b146c35
PCI: Avoid bus reset if bridge itself is broken

[ Upstream commit 357027786f3523d26f42391aa4c075b8495e5d28 ]

When checking to see if a PCI bus can safely be reset, we previously
checked to see if any of the children had their PCI_DEV_FLAGS_NO_BUS_RESET
flag set.  Children marked with that flag are known not to behave well
after a bus reset.

Some PCIe root port bridges also do not behave well after a bus reset,
sometimes causing the devices behind the bridge to become unusable.

Add a check for PCI_DEV_FLAGS_NO_BUS_RESET being set in the bridge device
to allow these bridges to be flagged, and prevent their secondary buses
from being reset.

Signed-off-by: David Daney <david.daney@cavium.com>
[jglauber@cavium.com: fixed typo]
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: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/pci/pci.c