Problem with xhci-hcd and Alfa AWUS036NHR

Problem with xhci-hcd and Alfa AWUS036NHR

[Larry Finger]

I am trying to help v4mp <gaigo88@hotmail.it> with a wireless problem.

He is running Ubuntu natty 3.0.4-030004-generic and get the following items in 
his dmesg output:

[    3.963920] xhci_hcd 0000:05:00.0: WARN: short transfer on control ep
[    3.970920] xhci_hcd 0000:05:00.0: WARN: short transfer on control ep
[    3.975037] xhci_hcd 0000:05:00.0: WARN: short transfer on control ep
[    3.976097] usb 3-2: ep 0x81 - rounding interval to 64 microframes, ep desc 
says 80 microframes
[    3.984899] xhci_hcd 0000:05:00.0: WARN: short transfer on control ep

and later many of

[  545.272708] xhci_hcd 0000:05:00.0: ERROR no room on ep ring

A nearly complete dmesg output is at http://pastebin.com/7tfcBfbD. I asked the 
OP to paste the entire output, but he gave me what is posted there.

Is there a bug in the rtl8192cu USB handling that would let the device work with 
ehci-hcd and ohci-hcd, but fail with xhci-hcd?

Would commit 44f4c3e (USB: xhci: Set change bit when warm reset change is set) 
have any effect on this? I do not know if this is in 3.0.4.

I did not find any other recent commits that are aimed at xhci and looked as if 
they might address this issue. Did I miss any?

Note: The Alfa device works fine on my system with only ohci and ehci controllers.

Thanks,

Larry