HelenOS sources

td_set_ioc        250 uspace/drv/bus/usb/uhci/uhci_batch.c 	td_set_ioc(&uhci_batch->tds[td - 1]);
td_set_ioc        324 uspace/drv/bus/usb/uhci/uhci_batch.c 	td_set_ioc(&uhci_batch->tds[td]);
HelenOS homepage, sources at GitHub