On Wed, 1 Jul 2009, Arseniy Lartsev wrote: > On Tuesday 30 June 2009 11:22:04 Oliver Neukum wrote: > > Yet, your device shows bulk endpoints. Please enable DEBUG in cdc-acm.c > > and recompile with CONFIG_USB_DEBUG. > > I've recompiled four modules usbcore, ehci_hcd, ohci_hcd and cdc-acm with -DDEBUG. > Here is kernel log: > > ======================== Device plugged in ======================== ... > Jun 30 23:58:35 noteb00k kernel: usb 2-3: new low speed USB device using ohci_hcd and address 5 ... > Jun 30 23:58:35 noteb00k kernel: usb 2-3: config 1 interface 1 altsetting 0 endpoint 0x1 is Bulk; changing to > Interrupt > Jun 30 23:58:35 noteb00k kernel: usb 2-3: config 1 interface 1 altsetting 0 endpoint 0x81 is Bulk; changing to > Interrupt This looks like your problem. Low-speed devices are not allowed to have bulk endpoints. Linux internally changes them to interrupt endpoints with interval = 1 and maxpacket size no larger than 8. 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