Subject: Re: USB 2.0 support - problems?
To: Jaromir Dolecek <>
From: Lennart Augustsson <>
List: tech-kern
Date: 01/04/2004 22:34:49
The EHCI driver lacks support for interrupt isochronous transfers.
Interrupt transfers are not difficult, it's just not done.
There might also be some issues with the data toggle, I never
managed to test if that works properly under all conditions.

The meaty part to implement is the support for USB 2.0 hubs.
They are quite compolicated since the need to be able to do
"transaction translation", i.e., converting to/from USB 2 and USB 1.
So the hub driver needs to handle and schedule these things.

	-- Lennart

Jaromir Dolecek wrote:
> Hi,
> what are the known issues with EHCI driver and USB 2.0 support?
> I'd like to eventually start looking at it.
> Jaromir