cvs commit: src/sys/dev/usb uhub.c

Bernd Walter ticso at cicely12.cicely.de
Sun Mar 20 17:55:07 PST 2005


On Mon, Mar 21, 2005 at 01:31:57AM +0000, Ian Dowse wrote:
> In message <20050321003007.GO53520 at cicely12.cicely.de>, Bernd Walter writes:
> >On Sun, Mar 20, 2005 at 11:45:00PM +0000, Ian Dowse wrote:
> >>   Log:
> >>   Root hubs don't have transaction translators, so skip printing the
> >>   message about them if the hub depth is zero.
> >
> >This is only true for the current hardware we support.
> >AFAIK the Philips ISP1761 is a EHCI derived USB On-The-Go controller
> >without companion controllers using a TT on the root hub.
> 
> Ok, thanks for the information - I guess we may need a different
> way to detect whether transaction translation is present. Although,
> just looking for information on the ISP1761, it might actually have
> a real non-root hub built in, as it claims to be EHCI compliant.

I stay corrected - you are absolutely right.
The datasheet says:
The ISP1761 implements an EHCI that has an internal port--the Root
Hub port (not available externally)--on which the internal hub is
connected. The three external ports are always routed to the internal
hub.  The internal hub is a Hi-Speed USB hub including the TT.

So from the drivers standpoint it's only special in that is has no
companion controllers.
Well - they mention some special handling in their data sheet as well,
but I asume that's more for optimizing in embedded designs.

-- 
B.Walter                   BWCT                http://www.bwct.de
bernd at bwct.de                                  info at bwct.de



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