HelenOS sources

req_status_change_handler  625 uspace/drv/bus/usb/ehci/ehci_rh.c 	.data_in[HUB_STATUS_CHANGE_PIPE] = req_status_change_handler,
req_status_change_handler  544 uspace/drv/bus/usb/ohci/ohci_rh.c 	.data_in[HUB_STATUS_CHANGE_PIPE] = req_status_change_handler,
req_status_change_handler  513 uspace/drv/bus/usb/uhci/uhci_rh.c 	.data_in[HUB_STATUS_CHANGE_PIPE] = req_status_change_handler,
HelenOS homepage, sources at GitHub