[Wylug-help] ehci_hcd

[Andy Macdonald]

For what it's worth ...

ehci_hcd is (almost certainly?) the Extended Host Controller Interface (Universal 2.0 USB Standard)

unic_hcd (?) - probably Universal Host Controller Interface (standard by Intel) - USB (1)

ohic_hcd (?) - OHCI - probably Open Host Controller Interface (standard by Compaq) - USB (1)

On Sun, 22 Oct, Linda Kennedy & David Carpenter wrote:
> Anyone know anything about this?
> 
> I use Ubuntu 6.06 and I've been having problems with my USB ports.
> 
> I can use my Epson printer and my Kodak camera both via the USB ports 
> and they work fine.
> 
> I have a USB Flash disc pen, and recently got an external hard drive, 
> neither of which 'hot-plugged' and in fact seemed to kill the USB ports 
> completely (so the printer wouldn't work after trying the hard drives in 
> the ports)
> 
> I've just found a solution that tells me to kill the ehci-hcd module 
> using the command:
> sudo modprobe -r ehci_hcd
> 
> and  when I do this  - the hard disks work! Great!
> ( I have to do this before I plug the USB pen in - if I do it afterwards 
> the terminal just seems to hang)
> 
> 
> I believe by killing off ehic_hcd,  uhic_hcd takes over and does the job 
> just fine.
> (BTW I think the camera works because it only tries to use ohic_ and 
> doesn't even bother ehic - not sure what the printer does)
> 
> Now I think uhic is USB 1, and ehic is USB 2 (the speed isn't too much 
> of a problem for what I do)
> 
> My question is: What do you think is going on?
> 
> I've searched some forums and can find the remove module solution, but 
> no real explanation. Is it just my hardware? Is there a problem with 
> ehic? Can I get USB 2 functionality at all?
> 
> Any comments welcome.
> 
> Cheers
> David
> 
> 
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-- 
Andy Macdonald
Network Manager, Greenhead College
Huddersfield, HD1 4ES, England.
01484 422032