Hello all I discover that new TT scheduler don't allow transfers longer than 780 uS (see max_tt_usecs[] in ehci-sched.c) or approx. 1000 bytes as calculated in iso_stream_init() for full speed isoc transfer. But, as I can understand from usb 2.0 documentation, limit for full speed isoc transfer is 1023 bytes as of table 5-4 sec 5.6.3. and it take approx. 806 uS Also, sec 5.6.4 declares that: "The USB requires that no more than 90% of any frame be allocated for periodic (isochronous and interrupt) transfers for full-speed endpoints. High-speed endpoints can allocate at most 80% of a microframe for periodic transfers." Can somebody explain scheduler limitation of 780 uS? Is it 78% of 1000 uS (8 microframes) or 89% of 875 uS (8 microframes minus SOF)? Why old scheduler allow 1023 bytes full speed isoc transfer but new one forbid this?? Regards, Leonid -- 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
