On 2014-05-19, Mike Larkin <mlar...@azathoth.net> wrote: > FWIW, I have 3 different uaudio dongles and they all work fine.
It depends on the layout of your USB bus, see "usbdevs -v". On older systems with USB2, full speed devices will be attached directly to a full speed root hub and the audio dongle will work. Here's an example from a Thinkpad X40: -------------------> Controller /dev/usb0: addr 1: high speed, self powered, config 1, EHCI root hub(0x0000), Intel(0x8086), rev 1.00 port 1 powered port 2 powered port 3 powered port 4 powered port 5 powered port 6 powered Controller /dev/usb1: addr 1: full speed, self powered, config 1, UHCI root hub(0x0000), Intel(0x8086), rev 1.00 port 1 powered port 2 powered Controller /dev/usb2: addr 1: full speed, self powered, config 1, UHCI root hub(0x0000), Intel(0x8086), rev 1.00 port 1 addr 2: full speed, power 20 mA, config 1, USB Audio DAC(0x2704), Burr-Brown from TI(0x08bb), rev 1.00 port 2 powered Controller /dev/usb3: addr 1: full speed, self powered, config 1, UHCI root hub(0x0000), Intel(0x8086), rev 1.00 port 1 powered port 2 powered <------------------- On systems with newer Intel chipsets that support USB3, full speed devices will be attached to a high speed rate-matching hub and the audio dongle will not work. I first noticed this on the Thinkpad X230 but mostly forgot about it. Here's an example from a PowerEdge T20: -------------------> Controller /dev/usb0: addr 1: high speed, self powered, config 1, EHCI root hub(0x0000), Intel(0x8086), rev 1.00 port 1 addr 2: high speed, self powered, config 1, Rate Matching Hub(0x8008), Intel(0x8087), rev 0.04 port 1 addr 3: low speed, power 100 mA, config 1, product 0x1203(0x1203), Holtek(0x04d9), rev 2.70 port 2 addr 4: low speed, power 100 mA, config 1, TEMPer sensor(0x660c), Ten X Technology, Inc.(0x1130), rev 1.50 port 3 addr 5: full speed, power 20 mA, config 1, USB Audio DAC(0x2704), Burr-Brown from TI(0x08bb), rev 1.00 port 4 powered port 5 powered port 6 powered port 2 powered port 3 powered Controller /dev/usb1: addr 1: high speed, self powered, config 1, EHCI root hub(0x0000), Intel(0x8086), rev 1.00 port 1 addr 2: high speed, self powered, config 1, Rate Matching Hub(0x8000), Intel(0x8087), rev 0.04 port 1 powered port 2 powered port 3 powered port 4 powered port 5 powered port 6 powered port 7 powered port 8 powered port 2 powered port 3 powered <------------------- Yes, I tried all ten USB ports on that machine. They're all routed to one of the rate-matching hubs. A potential workaround would be to plug a USB2 expansion card into the box, depending on what the bus layout will be there. I might try that, but at the moment the single PCI slot is already occupied. There should also be high speed USB audio devices, and possibly asynchronous ones, but this kind of information is difficult to discern from the packaging or the manual leaflets. -- Christian "naddy" Weisgerber na...@mips.inka.de
