On 11/18/2011 11:38 AM, Andrej Podzimek wrote:
Hello,
I am running kernel 3.0.8 on x86_64 (a Zotac mini-ITX motherboard with a
NEC USB 3.0 controller).
05:00.0 USB controller: NEC Corporation uPD720200 USB 3.0 Host
Controller (rev 03)
The problem is that USB 2.0 devices are not recognized at all when
connected to USB 3.0 ports. But USB 3.0 devices work just fine. For
instance, a Western Digital USB 3.0 hard disk appears in both lsusb (and
lsusb -t) and achieves transfer rates of more than 100 MB/s.
Bus 002 Device 008: ID 1058:0730 Western Digital Technologies, Inc.
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/2p, 5000M
|__ Port 2: Dev 2, If 0, Class=hub, Driver=hub/4p, 5000M
|__ Port 4: Dev 8, If 0, Class=stor., Driver=usb-storage, 5000M
(There is a Hama USB 3.0 hub connected to one of the USB 3.0 ports.
Tried to connect my devices with/without the hub and also with/without a
5 meters long "active cable" for USB 3.0. The hard drive achieved the
same transfer rates in all configurations.)
When it comes to USB 2.0 devices in USB 3.0 ports, they are silently
ignored and nothing appears in dmesg. Two different flash drives, two
different UVC cameras and a HP DVD writer -- all of them work normally
on USB 2.0 ports, but don't seem to be recognized at all on USB 3.0.
(The motivation behind using USB 3.0 hubs for USB 2.0 devices is a
multi-seat configuration with a USB 3.0 hub for each user, aiming to
provide fast USB connectivity with just one cable.)
How can I diagnose these problems? Is this a known issue? A hint would
help me a lot. :-)
Do you connect your USB2.0 devices to USB3 root hub or via a USB3.0
external hub?
I tried both combinations. A direct connection did not work either.
Surprisingly, it provoked a complete system freeze (with no reaction to
ping) after a couple of attempts. (However, this is not 100%
reproducible.) I didn't have netconsole configured, so I don't know what
exactly happened. Plugging the USB 2.0 devices to the USB 3.0 hub never
caused a freeze.
Please apply the two patches attached and see if they are useful.
Unfortunately, the patches did not bring any obvious improvement. My USB
3.0 hard drive worked as usual and legacy devices were ignored as usual.
The machine now runs kernel 3.1.1 (which seems to have these patches
already included) and there's still the same problem.
Haven't seen such issue on NEC uPD720200 before. Can you enable
CONFIG_USB_DEBUG and CONFIG_USB_XHCI_HCD_DEBUGGING, send the dmesg from
bootup, and specify the point when you hot plug a USB2.0 device to the
root hub?
Thanks,
Andiry
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