On 06/30/2014 05:43 PM, Alan Stern wrote: > On Mon, 30 Jun 2014, Mathias Nyman wrote: > >> xhci specs says it needs the interval rounded to nearest 2^(X) value, >> which would be 256, not 128. I'll take a look at that. > > Doesn't the spec says it needs the interval rounded _down_ to a > power of 2? > So it does, xhci 6.2.3.6 "software shall round the computed value of Endpoint Context Interval field down to the nearest base 2 multiple.." Seems quite brutal to round 255 to 128 instead of 256. I guess its better to schedule a transfer too often than not enough -Mathias -- 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