diff options
| -rw-r--r-- | MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c index 157a0ad..419f47a 100644 --- a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c +++ b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c @@ -1238,6 +1238,16 @@ RootBridgeIoPciAccess ( }
}
+ //
+ // If the access was a PCI write, it might have side effects that impact how
+ // the PCI device decodes its MMIO regions. Issue a barrier to ensure that
+ // subsequent MMIO accesses to those regions will not be reordered, and will
+ // not arrive before the PCI write.
+ //
+ if (!Read) {
+ MemoryFence ();
+ }
+
return EFI_SUCCESS;
}
|