Messages in this thread | | | Date | Tue, 23 Sep 2008 11:07:09 -0700 | From | Greg KH <> | Subject | Re: USB driver problem with external hub |
| |
On Sat, Sep 20, 2008 at 04:35:03PM -0700, cihan öztürk wrote: > I am working on a device driver for providing connectivity to a Silabs > F340 board through USB. All the required software, including firmware > on the device side, USB device driver and user level libraries as well > as the application, are implemented. The system operates fine when > experimental communication is considered, in which dummy data is > simply sent and received betweeen the host and the device at Full > speed. The trouble comes when a USB external hub is used as a gateway > between the device and the host instead of directly connecting the USB > cable from device to the USB port of the PC. The kernel log states > that the transfer of urb failed due to -EPROTO(-71), which is defined > as protocol error. I found in some resources that this error can be a > result of (a) bitstuff error, or (b) no response packet received > within the prescribed bus turn-around time, or (c)hardware problems > such as bad devices (including firmware) or cables. > The hub is a Digitus product with 7 ports and works fine with other > USB devices such as the mouse on the same platform. > My kernel version is 2.6.18.
Is this because you are using a USB 2.0 hub, connected via EHCI and your device is a 1.1 speed device? If so, this is a known issue with older kernel versions, and has partially been fixed in newer kernel releases.
Please try 2.6.26 and let us know if that solves the issue.
Or just use a 1.1 hub, that should also work.
thanks,
greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |