the problem appears to be that most USB hubs (like my port replicator) only support asynchronous transfer while audio devices need isochronous transfers. That would mean, most likely, that if I plugged a hub that supports isochronous transfer, for example the griffin hub, into my asynchronous docking station I would still have problems... # lsusb -v | grep Synch just gives numerous Synch Type none listings so it looks like i have to ditch the docking station unless anyone else can think of something :( Thanks again, - Jonathan Beilin >From: Steve Harris <S.W.Harris@xxxxxxxxxxxxxxx> >Reply-To: A list for linux audio users ><linux-audio-user@xxxxxxxxxxxxxxxxxx> >To: linux-audio-user@xxxxxxxxxxxxxxxxxx >Subject: Re: [linux-audio-user] USB Audio + docking station/powered >hub(audiotrak optoplay) >Date: Thu, 1 Apr 2004 23:04:48 +0100 > >On Thu, Apr 01, 2004 at 12:36:28PM -0800, Jonathan Beilin wrote: > > Hi, I'm running gentoo on a dell inspiron 8600 with a docking station & >a > > powered USB hub. When I'm undocked with the audiotrak optoplay plugged >in > > directly, it works fine. However, if I try to plug the optoplay in to >the > > docking station or the wall-wart powered USB hub the optical-digital >light > > is very faint and I get broken pipe reports when I send a signal to the > > device. What is wrong? > >Thats interesting. This product: >http://www.griffintechnology.com/products/usbaudio_hub/ claims to be a >"USB Audio" hub, and I always thought it was BS, but maybe theres some >truth in it. > >Sorry I dont have any helpful suggestions :( It could be that the audio >device is trying to draw more power from a single port than the hub or >docking station wants to provide, you can find out by running lsusb -vv as >root and looking for the MaxPower line of your audio device and the power >allowance (dunno what thats called) of the hub. The docking station will >probably be a hub too. > >- Steve _________________________________________________________________ Limited-time offer: Fast, reliable MSN 9 Dial-up Internet access FREE for 2 months! http://join.msn.com/?page=dept/dialup&pgmarket=en-us&ST=1/go/onm00200361ave/direct/01/
