Hello, On Sun, 25 Jul 2010, Sam Gentle wrote: > When I attempt to record from it, I get "ALSA start: broken pipe" and > this error in my dmesg: "cannot submit datapipe for urb 0, error -28: > not enough bandwidth" I have a similar problem with a 4-in/2-out USB soundcard called Lexicon Omega. Using Ubuntu Maverick, I wrote to the Ubuntu Forums ( http://ubuntuforums.org/showthread.php?t=1603137 ) and they told me to ask alsa-devel list, which wrote that this problem is USB related. When using the device as 2-in/2-out it works fine, but when trying to get 4-in, bandwidth message appears and audio I/O stops. When using the device in simplex mode, it works as expected, but it is necessary for me, to have duplex with 4/2. I am using kernel 2.6.35 and alsa 1.0.23 (both Ubuntu shipped). The kernel is configured with CONFIG_USB_EHCI_TT_NEWSCHED=y The soundcard is connected directly to the notebook, however, there are internal USB devices: a webcam and a fingerprint sensor. output of lsusb without soundcard: Bus 002 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 004: ID 04f2:b130 Chicony Electronics Co., Ltd Bus 001 Device 003: ID 08ff:168b AuthenTec, Inc. Bus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Alan Stern suggested the following: > For now, your best bet may be to force the built-in hub to connect at > full speed instead of high speed. You can do this by writing the hub's > port number to the "companion" file in the EHCI controller's sysfs > directory. For example, in your "connect" log the hub was attached to > port 6 on bus 1, so you could do: > > echo 6 >/sys/bus/usb/devices/usb1/../companion I tried that, but with "1" and "2", as the hub is device 1 and 2 on Bus 2, but it did not work (hub just stopped working). The output of lsusb -v is attached (before fiddling with companion). Is there anything else I can post here or try on my system? Any hint is greatly appreciated! Thank you very much Daniel StÃckner
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