PciIoAttributes() in PciIo.c treats EFI_PCI_DEVICE_ENABLE specially so that when EFI_PCI_DEVICE_ENABLE is passed in, only the supported bits of driver will be enabled. Now many drivers use EFI_PCI_DEVICE_ENABLE to enable PCI device even if some of them don't support some of the attributes like EFI_PCI_IO_ATTRIBUTE_MEMORY. This doesn't conform to UEFI 2.0 spec.
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@4115 6f19259b-4bc3-4df7-8a09-765794883524