On Sat, 12 Sep 2009, Toan Pham wrote: > >> Everything works fine if i blacklisted USBHID driver. It seems the > >> problem is not in my CDC device's hardware or software because I > >> tested the device on multiple machines before. > > > > If there's nothing wrong with the CDC device then why does it generate > > all those error messages in the log? > > That is really my problem, conflicting with USBHID driver somehow. > When USBHID driver is not attached, there are no transfer errors at > all (no kernel log messages). > Also, even when USBHID driver is attached and the CDC device is > plugged into the ebox on another USB port and attached to EHCD, > there are also no transfer errors. > While developing the CDC device, i also used Beagle 480 USB protocol > analyzer and diagnosed > traffic. All transactions were clean. I am not convinced that the > root cause is in the CDC device. It could be a problem in the OHCI controller. Can you put a protocol analyzer between the controller and the CDC device? If the analyzer shows good transfers and the OHCI controller continues to report all those errors, then the controller isn't working right. 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
