Re: Handling of bounce buffers by rh_call_control

[David Brownell]

Richard Curnow wrote:
> IIRC, if I plug a USB2 device into a USB2 card but don't have the EHCI
> driver active, the device is just ignored, rather than falling back to
> using USB1.1 through OHCI?  We certainly have some USB2 devices we'd
> like to use, even if the USB2 bandwidth might be throttled back by the
> bounce buffering overhead.

Yes, high speed USB transfers need the EHCI driver.
If that driver isn't running, then OHCI (or UHCI)
should kick in.  (Assuming that driver is running!)

Most high speed storage seems to work with the current
EHCI code, although some hardware acts unhappy when
Linux talks to it faster than Windows does.  That's
more of an issue on 2.6 than on 2.4 though.

- Dave



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