CPC_PCI_BRDGERR
erren = pci_conf_read(pc, tag, CPC_PCI_BRDGERR);
pci_conf_write(pc, tag, CPC_PCI_BRDGERR, 0);
pci_conf_write(pc, tag, CPC_PCI_BRDGERR, erren | CPC_PCI_CLEARERR);