From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pablo Yaggi Subject: Re: C-Media / usb device bug ? Date: Tue, 19 Sep 2006 04:17:50 -0300 Message-ID: <200609190417.50321.pyaggi@alsurdelsur.com> References: <200609181921.10510.pyaggi@alsurdelsur.com> <1158647803.13410.271265867@webmail.messagingengine.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <1158647803.13410.271265867@webmail.messagingengine.com> Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@lists.sourceforge.net Errors-To: alsa-devel-bounces@lists.sourceforge.net To: Clemens Ladisch Cc: alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org On Tuesday 19 September 2006 03:36, Clemens Ladisch wrote: > Pablo Yaggi wrote: > > I'm working in a multi-capture application with alsa and i discovered > > if i attach two "c-media usb headphone set" adapters to an usb hub which > > is attached to my computer when i try to read from the two devices the > > first one read (also open) errors with (-77) bad file descriptor status > > and the other one keep working. When i attach the two devices directly = to > > the usb connectors (without hub) all works fine, the two devices can be > > read at the same time. > = > What kernel version are you using? > = > The EHCI transaction translator code (which is responsible for moving > audio data through an high speed hub) got a bugfix in 2.6.17, but still > artificially limits the bandwidth. It will be rewritten in 2.6.18. > = > = > HTH > Clemens > = I tested it on 2.6.15, 2.6.16 and 2.6.17, so you think the problem is EHCI ? =A0is there anyway to check it ? is it yet in rewriting process ? = Thank's Pablo ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=3Djoin.php&p=3Dsourceforge&CID=3DDE= VDEV