Return-Path: To: bluez-users@lists.sourceforge.net Subject: Re: [Bluez-users] USB/Bluetooth dongle doesn't work in hub References: <1099959115.29330.40.camel@pegasus> <1099985025.29330.52.camel@pegasus> From: Scott W Gifford In-Reply-To: <1099985025.29330.52.camel@pegasus> (Marcel Holtmann's message of "Tue, 09 Nov 2004 08:23:45 +0100") Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: bluez-users-admin@lists.sourceforge.net Errors-To: bluez-users-admin@lists.sourceforge.net Reply-To: bluez-users@lists.sourceforge.net List-Unsubscribe: , List-Id: BlueZ users List-Post: List-Help: List-Subscribe: , List-Archive: Date: Wed, 01 Dec 2004 19:33:24 -0500 Marcel Holtmann writes: [...] >> As before, they work fine when plugged directly into the laptop. > > go ahead and report this problem to the USB mailing list, because it is > not a Bluetooth problem and I don't know why this fails. I didn't get an answer on the USB mailing list, but I saw another related answer that seemed to help. Apparently using certain types of transfers on a high-speed hub with a low-speed device is still unsupported: http://www.linux-usb.org/usb2.html In terms of functionality, the latest driver: [...] * Has partial support for split transactions (full and low speed transfers) through USB 2.0 hubs: [...] o You can't (yet) use full speed isochronous transfers through USB 2.0 hubs. (At least without an experimental patch.) That means: don't hook up USB 1.1 webcams, speakers, etc. to high speed buses, they'll enumerate but you won't be able to use them otherwise. Eventually of course a dozen USB 1.1 webcams will easily coexist at full data rate on a single USB 2.0 bus, using USB 2.0 hubs. The "ehci-hcd" module provides support for high-speed USB 2.0. Removing it with rmmod makes everything run as low-speed USB 1.x, and that seems to solve the problem. I tested with the dongles I have: D-link DBT-120, Belkin F8T001, AmbiCom BT2000, and IOGear GBU211. I tested plugged directly in, plugged into a hub connected directly, and plugged into a hub connected to a hub connected to a hub connected directly. -----ScottG. ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/ _______________________________________________ Bluez-users mailing list Bluez-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bluez-users