On Fri, 14 Feb 2014, vichy wrote: > hi Alan: > > > I don't understand your question. > > > > At full speed (12 Mb/s), the time required to transfer 188 bytes is > > > > (188 bytes) * (8 bits/byte) / (12 b/us) = 125.33 us, > > > > which is greater than 125 us. > > @@ -1412,7 +1412,7 @@ sitd_slot_ok ( > */ > uf = uframe & 7; > if (!tt_available(ehci, period_uframes >> 3, > - stream->udev, frame, uf, stream->tt_usecs)) > + stream->udev, frame, uf, stream->usecs)) > > if so, shall we modify code like above? > Use transfer time instead of bus budget to calculate tt_avaiable? No. stream->usecs is the time required on the high-speed bus, and stream->tt_usecs is the time required on the full/low-speed bus. tt_available makes its decisions based on whether there is enough available time on the full/low-speed bus. Therefore it needs to use stream->tt_usecs. 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
