On Mon, 13 Dec 2010, Sergej Pupykin wrote: > 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. ... > It was the same machine (toshiba laptop with uhci controller) You should change your program to install configuration 0 (i.e., unconfigure the device) before carrying out the data transfer. That will limit the transfer rate to one transaction per ms -- provided you continue to use a UHCI controller. 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
