Re: [gentoo-user] Which USB device on which controller?

[Grant <emailgrant@gmail.com>]

>> You seem to be right on here Dale.  usbview showed my printer
>> connected to the 2.0 controller and a webcam connected to the 1.1
>> controller, so I unplugged the printer and plugged the webcam into
>> it's slot and it still showed up under 1.1.  So there doesn't appear
>> to be any slot/controller correlation.
>>
>> This is a problem for me though.  My webcams can't both operate on the
>> 1.1 controller at the same time due to the bandwidth limitation of the
>> 1.1 controller.  I need them both on 2.0 or one on each controller,
>> but they are always grabbed by the 1.1 controller.  Even worse, I
>> disabled support for 1.1 in the kernel so only 2.0 was supported and
>> the webcams didn't show up at all.  Could they be USB 1.1 only?
>> Shouldn't a 1.1 device operate on a 2.0 controller?
>>
>> - Grant
>>
>>
>>
>
>
> This is how I understand it.  Any 2.0 device should work with the older
> 1.0 version, just slower.  Backwards compatible.  However, like with my
> camera, if the device is a version 1.0, it will only work in 1.0 mode.
> If you recently purchased this, you may want to exchange it and make
> sure you get a 2.0 version.  That is if there is such a creature.
>
> The reason behind this is the chip inside the camera/webcam itself.  The
> cable can cause this if it is not made for the new higher bandwidth or
> is crappy but if the chip in there is the old 1.0 version, it can't go
> any faster.
>
> Another idea, you may be able to get a card to expand your USB ports and
> see if that will help.  Each card has its own chip as well.  Put one
> device on the card and one on the mobo port.  That way they are seen and
> controlled by separate chips.  That should help with the bandwidth
> problem at least.
>
> Dale

I'm looking at the box of one of the webcams and it says "USB 2.0
compatible".  It's not a cable problem because the cable is built
right into the webcam.  I'm not trying to get the webcam to go faster
back and forth to the controller, I just need to make sure I don't
have both webcams on the same OHCI (1.1) USB controller.  I would
think buying a USB expansion card would work, but I have an EHCI (2.0)
controller on this system and a second OHCI (1.1) controller.

Does anyone have any idea on this.  It really doesn't make sense.

- Grant