| USB_CALC_BUS_TIME(9) | Host Controller APIs | USB_CALC_BUS_TIME(9) |
NAME¶
usb_calc_bus_time - approximate periodic transaction time in nanoseconds
SYNOPSIS¶
long usb_calc_bus_time(int speed, int is_input, int isoc, int bytecount);
ARGUMENTS¶
speed
from dev->speed; USB_SPEED_{LOW,FULL,HIGH}
is_input
true iff the transaction sends data to the host
isoc
true for isochronous transactions, false for interrupt
ones
bytecount
how many bytes in the transaction.
RETURN¶
Approximate bus time in nanoseconds for a periodic transaction.
NOTE¶
See USB 2.0 spec section 5.11.3; only periodic transfers need to be scheduled in software, this function is only used for such scheduling.
COPYRIGHT¶
| June 2024 | Kernel Hackers Manual 3.10 |