Date: Sat, 07 Aug 2004 15:59:20 -0600 (MDT) From: "M. Warner Losh" <imp@bsdimp.com> To: dmp@bitfreak.org Cc: chris@tellme3times.com Subject: Re: USB drivers Message-ID: <20040807.155920.66760165.imp@bsdimp.com> In-Reply-To: <000001c47cb8$8ef1bb50$142a15ac@spud> References: <20040806.231231.33567668.imp@bsdimp.com> <000001c47cb8$8ef1bb50$142a15ac@spud>
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In message: <000001c47cb8$8ef1bb50$142a15ac@spud>
"Darren Pilgrim" <dmp@bitfreak.org> writes:
: > From: M. Warner Losh
: >
: > In message: <41124C8B.2060902@tellme3times.com>
: > Chris <chris@tellme3times.com> writes:
: > :
: > : What I am trying to determine is why my multifunction
: printer/scanner
: > : receives only one of the two drivers. Is it because the printer
: does
: > : not respond properly? Is it because the printer is not defined? I
: > : have many questions here.
: >
: > Yes. Usb is a little complicated in this area, and there are a number
: > of details that are hard to get right. It wouldn't surprise me if the
: > current set of drivers are less than completely optimal.
:
: On a bit of a side-track, I'm wondering if it could be due to how the
: multifunction device presents itself? A bit back in this thread someone
: mentioned that a pointer must be present for a driver to attach to a
: device. If there is only one pointer for a device, only one driver may
: attach. Since a single USB bus can have a LOT of devices and each
: device's capabilities are determined through the presence of usage
: pages, I see two ways for a multifunction device to present itself:
:
: - A single device ID with more than one usage page. All the
: functionality is there and is compatible with FreeBSD drivers, but since
: there is only one device probed on the bus, only one driver may attach.
: Perhaps a "simple" mux driver would be useful?
:
: - A multiple single-usage device IDs. Same functionality as before, but
: now FreeBSD can probe unique printer and scanner devices and thus let
: both ulpt and uscanner attach simutaneously.
:
: Am I way off base?
No. You are exactly on base. That's why I pointed at you at the usb
information program. Run it with the device plugged in, and we'll be
able to know the details.
Warner
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