On Thu, 7 May 2009, Oliver Neukum wrote: > > How about setting the upper limit to URBs in flight based on the baud > > rate? Faster transfers deserve more URBs, right? Assuming some > > minimum number of bytes per URB (4? 8?), there should be enough URBs to > > fill a pipeline whose length is around 5 ms or so (interrupt latency). > > Hm, you say many URBs can complete before an interrupt handler > can react? How long can interrupts remain disabled? On a non-RT system, it might be several milliseconds. In any case, a full-speed host controller won't issue IRQs more often than once per ms. Quite a few URBs can complete in that time. 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
