kern/47522: Enumeration of LUFA/Atmel devices on UHCI fails

[jakllsch%kollasch.net@localhost]

>Number:         47522
>Category:       kern
>Synopsis:       Enumeration of LUFA/Atmel devices on UHCI fails
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Feb 01 23:30:01 +0000 2013
>Originator:     Jonathan Kollasch
>Release:        6.0
>Organization:
>Environment:
amd64
>Description:
Enumeration of Atmel's AT90USBx2 DFU firmware loader, as well
as any LUFA-based device firmware (at least when running on an AVR8
micro-controller) fail to enumerate when connected to a NetBSD UHCI
root hub.

USB analyzer traces indicate that the request for the initial device
descriptor (the one obtained while the device is at address 0) are
not correctly executed by the host controller.  However most devices
do not trip over this problem.

During this first request to a plugged device, the SETUP and IN phases
happen (apparently) normally, however the final OUT phase does not occur.
This may cause the state machine in the firmware of some devices to not
accept the address assignment.
>How-To-Repeat:
Plugging an Atmel and/or LUFA device into UHCI root hub port
results in "device problem, disabling port" message from kernel.
When plugged into a NetBSD OHCI root hub or a USB 2.0 hub
(via transaction translator), it enumerates as expected.

I have only experienced this problem on Intel (ICH7) UHCI controllers,
however I haven't tried other Intel or VIA UHCIs.
>Fix: