At Mon, 13 Dec 2010 12:21:43 -0500 (EST), Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > According to USB sniffer it transfers data much faster than 64byte > > packet per ms. How can I limit it? > > Does this listing show the device's state after the firmware has been > loaded? The only endpoint it shows is the default control endpoint > (endpoint 0). You cannot limit the transfer rate for control > transfers(*), but you can limit the rate for other types of transfer. > > (*) This isn't entirely true. If you are using uhci-hcd then control > transfers are limited to one packet (64 bytes for your device) per ms > whenever the device is unconfigured. Your program should avoid sending > a Set-Configuration request. But with ohci-hcd there is no way to > affect the transfer rate; it is handled entirely by the hardware. > Can you post traces showing the device working under Windows and > failing under Linux? Here are sniffs (also available in single archive usb-dumps.tar.gz) http://arch.pp.ru/~sergej/files/usb-dumps/ .csv-exported and original in .tdc format. .tdc can be viewed by beagle-data-center (can be downloaded from http://www.totalphase.com/products/beagle_usb480/ ) If I expand 1023bytes packet sniffed on linux I get: 0:01.931.666,50.083 us,64 B,,03,00, IN txn... 0:01.931.719,50.250 us,64 B,,03,00, IN txn... 0:01.931.772,50.083 us,64 B,,03,00, IN txn... .... On windows: 5:29.963.753,50.166 us,64 B,,01,00, IN txn... 5:29.964.753,50.500 us,64 B,,01,00, IN txn... 5:29.965.753,50.083 us,64 B,,01,00, IN txn... It was the same machine (toshiba laptop with uhci controller) -- 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
