[PATCH] pcie: Restore ACS configuration as part of pci_restore_state

[Alexander Duyck <alexander.h.duyck@redhat.com>]

This change is meant to address the fact that ACS state was not being
restored as a part of the PCI configuration restoration following a PCIe
reset.  Without this patch it is not possible to reassign interfaces behind
ACS enabled switches following a system suspend as all of the ACS
functionality is disabled due to the D0->D3->D0 state transition cycle
clearing the configuration state and the fact that the ACS logic was only
initialized in probe.

Cc: Allen Kay <allen.m.kay@intel.com>
Cc: Chris Wright <chris@sous-sol.org>
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
---
 drivers/pci/pci.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 0008c950452c..9bd9526f3388 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1092,6 +1092,9 @@ void pci_restore_state(struct pci_dev *dev)
 
 	pci_restore_pcix_state(dev);
 	pci_restore_msi_state(dev);
+
+	/* Restore ACS and IOV configuration state */
+	pci_enable_acs(dev);
 	pci_restore_iov_state(dev);
 
 	dev->state_saved = false;