Date: Mon, 21 Mar 2005 02:54:39 +0100 From: Bernd Walter <ticso@cicely12.cicely.de> To: Ian Dowse <iedowse@maths.tcd.ie> Cc: cvs-all@freebsd.org Subject: Re: cvs commit: src/sys/dev/usb uhub.c Message-ID: <20050321015438.GP53520@cicely12.cicely.de> In-Reply-To: <200503210131.aa69950@salmon.maths.tcd.ie> References: <20050321003007.GO53520@cicely12.cicely.de> <200503210131.aa69950@salmon.maths.tcd.ie>
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On Mon, Mar 21, 2005 at 01:31:57AM +0000, Ian Dowse wrote: > In message <20050321003007.GO53520@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@bwct.de info@bwct.de
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