tree 07189bb010c1d9443a0fee736268cfcbf965dfd3
parent 26833a5029b710b12f00607fa255ce86909836ad
author Gavin Shan <gwshan@linux.vnet.ibm.com> 1398326424 +1000
committer Benjamin Herrenschmidt <benh@kernel.crashing.org> 1398670493 +1000

powerpc/pci: Mask linkDown on resetting PCI bus

The problem was initially reported by Wendy who tried pass through
IPR adapter, which was connected to PHB root port directly, to KVM
based guest. When doing that, pci_reset_bridge_secondary_bus() was
called by VFIO driver and linkDown was detected by the root port.
That caused all PEs to be frozen.

The patch fixes the issue by routing the reset for the secondary bus
of root port to underly firmware. For that, one more weak function
pci_reset_secondary_bus() is introduced so that the individual platforms
can override that and do specific reset for bridge's secondary bus.

Reported-by: Wendy Xiong <wenxiong@linux.vnet.ibm.com>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>