NEC Chipset cardbus USB2 card not working in high speed mode - any hints?

James Wilkinson james at westexe.demon.co.uk
Wed Dec 15 13:14:00 UTC 2004


Charles E Taylor IV wrote:
> There's only two ports on this card, and both work at high speed on Fedora
> Core 1 (and for that matter, Redhat 9).  Neither port works at full speed
> on Fedora Core 3, and both give the same "ehci_hcd fatal error" message.

Can I just note that when USB 1 was brought in, "full speed" was defined
to be 12 Mbit/s (which was full speed for those devices). The 480 Mbit/s
that USB 2 can provide was, years after USB1 was specified, called "high
speed" (or "hi speed").

And "full speed" was not redefined: to this day, it remains 2.5% of what
a USB 2 port can do.

And so you can get full speed USB 2 devices that only do 12 MBit/s.

I've no idea whether this has any bearing on the original problem...

James.
-- 
E-mail address: james | "It has taken 24 years to get the Reichstag wrapped.
@westexe.demon.co.uk  | Chancellor Kohl said it would only be wrapped over
                      | his dead body, so sensing an opportunity the
                      | Bundestag outvoted him."  -- The Guardian




More information about the fedora-list mailing list