HelenOS sources
usb_log_printf 57 uspace/lib/usb/include/usb/debug.h usb_log_printf(USB_LOG_LEVEL_FATAL, format, ##__VA_ARGS__)
usb_log_printf 61 uspace/lib/usb/include/usb/debug.h usb_log_printf(USB_LOG_LEVEL_ERROR, format, ##__VA_ARGS__)
usb_log_printf 65 uspace/lib/usb/include/usb/debug.h usb_log_printf(USB_LOG_LEVEL_WARNING, format, ##__VA_ARGS__)
usb_log_printf 69 uspace/lib/usb/include/usb/debug.h usb_log_printf(USB_LOG_LEVEL_INFO, format, ##__VA_ARGS__)
usb_log_printf 73 uspace/lib/usb/include/usb/debug.h usb_log_printf(USB_LOG_LEVEL_DEBUG, format, ##__VA_ARGS__)
usb_log_printf 77 uspace/lib/usb/include/usb/debug.h usb_log_printf(USB_LOG_LEVEL_DEBUG2, format, ##__VA_ARGS__)
HelenOS homepage, sources at GitHub