OHCI1394_IntEventClear
reg_write(ohci, OHCI1394_IntEventClear,
reg_write(ohci, OHCI1394_IntEventClear, 0xffffffff);
reg_write(ohci, OHCI1394_IntEventClear, OHCI1394_busReset);
event = reg_read(ohci, OHCI1394_IntEventClear);
reg_write(ohci, OHCI1394_IntEventClear,
reg_write(ohci, OHCI1394_IntEventClear,
reg_write(ohci, OHCI1394_IntEventClear, ~0);