[Gllug] Dell Latitudes D830 USB problem....

[James Courtier-Dutton]

On 19 April 2012 00:25, Christopher Hunter <cehunter at gb-x.org> wrote:
> Finally, I've made some minor progress - the "USB device cannot be
> enumerated" persists, but I've found out that the USB ports are only USB
> 1.1, not USB 2....
>
> Ubuntu 11.10 (and several other modern distros I've tried) don't seem to
> handle USB 1.1.  Has anyone got a fix for this - some clever driver or
> kernel patch that'll allow me to downgrade to USB 1.1?
>

I think your hope for a fix is flawed.

Linux quad 3.1.1 #5 SMP Tue Apr 17 08:37:05 BST 2012 x86_64 x86_64
x86_64 GNU/Linux
lsusb -v
Extract:
Bus 006 Device 003: ID 045e:00db Microsoft Corp. Natural Ergonomic
Keyboard 4000 V1.0
Device Descriptor:
  bcdUSB               2.00

Bus 002 Device 007: ID 045e:0039 Microsoft Corp. IntelliMouse Optical
Device Descriptor:
  bcdUSB               1.10


So, I have a keyboard that is USB 2.0 and a Mouse that is USB 1.1 and
they are both working on kernel 3.1.1
So, the latest Linux kernel does support USB 1.1 devices.

FYI, there are actully two different drivers, one does 1.1 and the
other does 2.0
>From lspci, you have for USB 1.1 uhci_hcd:
00:1a.0 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB
UHCI Controller #4 (prog-if 00 [UHCI])
        Subsystem: ASUSTeK Computer Inc. Device 82d4
        Flags: bus master, medium devsel, latency 0, IRQ 16
        I/O ports at b800 [size=32]
        Capabilities: [50] Vendor Specific Information: Len=06 <?>
        Kernel driver in use: uhci_hcd

you have for USB 2.0 ehci_hcd:
00:1a.7 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB2
EHCI Controller #2 (prog-if 20 [EHCI])
        Subsystem: ASUSTeK Computer Inc. Device 82d4
        Flags: bus master, medium devsel, latency 0, IRQ 18
        Memory at fe4ff000 (32-bit, non-prefetchable) [size=1K]
        Capabilities: [50] Power Management version 2
        Capabilities: [58] Debug port: BAR=1 offset=00a0
        Capabilities: [98] Vendor Specific Information: Len=06 <?>
        Kernel driver in use: ehci_hcd


So, if your motherboard only does USB 1.1, it should have uhci_hcd
next to the USB hardware.

Note the a USB 2.0 device does not have to work with a USB 1.1 port,
some devices support both USB 2.0 and USB 1.1, but not all.
A USB 2.0 port should work with USB 1.1 and USB 2.0 devices.

I think your problem is that you have a USB 2.0 device that cannot
work with a USB 1.1 port.

If you do a lspci -v, and see any ehci_hcd, it means you have USB 2.0
capable ports.
If you do a lspci -v, and all you see is uhci_hcd, it means you have
USB 1.1 capable ports.

If you spot a ehci_hcd, then it could be that only one port is USB 2.0 capable.

Kind Regards

James
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