列表 5. 读写 PCI 内存

pci_read_config_byte (dev, PCI_LATENCY_TIMER,
                      &latency);
if (latency) {
    pci_read_config_byte (dev, PCI_MAX_LAT, &limit);
    if (limit && limit < latency) {
        dbg ("PCI latency reduced to max %d", limit);
        pci_write_config_byte (dev, PCI_LATENCY_TIMER,
                               limit);
        ohci->pci_latency = limit;
    } else {
        /* it might already have been reduced */
        ohci->pci_latency = latency;
    }
}