LinuxQuestions.org - USB mouse and USB DAC can't be used simultaneously

Hi,

I have a USB mouse and a USB audio DAC.

Both work fine separately with linux.

The problem is when I try using both simultaneously. The first-plugged device will work fine, but not the second-plugged device. That is, if I plug the mouse first and the DAC second, then the mouse works and the DAC doesn't work. And conversely.

When I say that the second-plugged device doesn't work, here's what I mean: the USB device is detected by the system, but gets "reset" every 2 seconds and can't be actually used at all.

Here are some log messages. Here I'm working in the case where I have plugged the mouse first and am plugging the DAC second.

Code:

$ lsusb | egrep -i mouse\|texas

Bus 002 Device 009: ID 08bb:2704 Texas Instruments Japan 

Bus 002 Device 007: ID 046d:c526 Logitech, Inc. MX Revolution Cordless Mouse

"Texas Instruments" is my DAC. So, at the level of lsusb, all is well.

Now here is what appears in /var/log/messages.log when I plug that DAC:

Code:

$ sudo tail -f /var/log/messages.log

Mar 26 08:33:25 kiwi kernel: usb 2-1.3: reset full speed USB device using ehci_hcd and address 9

Mar 26 08:33:26 kiwi kernel: usb 2-1.3: reset full speed USB device using ehci_hcd and address 9

Mar 26 08:33:26 kiwi kernel: usb 2-1.3: reset full speed USB device using ehci_hcd and address 9

Mar 26 08:33:27 kiwi kernel: usb 2-1.3: reset full speed USB device using ehci_hcd and address 9

Mar 26 08:33:28 kiwi kernel: usb 2-1.3: reset full speed USB device using ehci_hcd and address 9

Mar 26 08:33:28 kiwi kernel: usb 2-1.3: reset full speed USB device using ehci_hcd and address 9

Mar 26 08:33:28 kiwi kernel: usb 2-1.3: reset full speed USB device using ehci_hcd and address 9

Mar 26 08:33:29 kiwi kernel: usb 2-1.3: reset full speed USB device using ehci_hcd and address 9

Mar 26 08:33:29 kiwi kernel: usb 2-1.3: reset full speed USB device using ehci_hcd and address 9

Mar 26 08:33:30 kiwi kernel: usb 2-1.3: reset full speed USB device using ehci_hcd and address 9

Mar 26 08:33:31 kiwi kernel: usb 2-1.3: reset full speed USB device using ehci_hcd and address 9

Mar 26 08:33:31 kiwi kernel: usb 2-1.3: reset full speed USB device using ehci_hcd and address 9

Mar 26 08:33:31 kiwi kernel: usb 2-1.3: reset full speed USB device using ehci_hcd and address 9

Mar 26 08:33:32 kiwi kernel: usb 2-1.3: reset full speed USB device using ehci_hcd and address 9

Mar 26 08:33:33 kiwi kernel: usb 2-1.3: reset full speed USB device using ehci_hcd and address 9

Mar 26 08:33:33 kiwi kernel: usb 2-1.3: reset full speed USB device using ehci_hcd and address 9

Mar 26 08:33:34 kiwi kernel: usb 2-1.3: reset full speed USB device using ehci_hcd and address 9

Mar 26 08:33:34 kiwi kernel: usb 2-1.3: reset full speed USB device using ehci_hcd and address 9

Mar 26 08:33:34 kiwi kernel: usb 2-1.3: reset full speed USB device using ehci_hcd and address 9

Accordingly, in alsamixer, the DAC appears as a sound card, but when I select it, after 2 seconds alsamixer tells me that it was unplugged.

Again, if I plug the DAC first then it works and when I then plug the mouse, I get the exact same problem for the mouse!

Any help greatly appreciated :)

My system:

Code:

$ uname -a

Linux kiwi 2.6.33-ARCH #1 SMP PREEMPT Sat Feb 27 13:28:30 CET 2010 x86_64 Intel(R) Core(TM) i7 CPU Q 720 @ 1.60GHz GenuineIntel GNU/Linux