On Mon, 23 Mar 2009, Richard wrote: > Thanks very much for all your help. > > I tried setting the priority of my program with the > setpriority() function, but it made no difference in > the usb timing. Is that how I should change the > program's priority? You should try sched_setparam() and sched_setscheduler(). Use the SCHED_FIFO policy. You should also have your program print out the current time just before and after each of the USB transfers. Comparing those values to the values from usbmon will provide some clues. > I also have a general question - given that this > device enumerates as a HID device, how is it that > the HID driver never enters into the picture? I can't tell you in detail because you didn't describe exactly how your program works. However, if the HID driver were bound to your device then your program would not be allowed to access the interrupt endpoints. Does your program call usb_detach_kernel_driver_np()? If it does, that removes the HID driver from the picture. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
