Arch Linux

Hi,

I have a USB mouse and a USB audio DAC.

Both work fine separately on my system.

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

If I then unplug the first-plugged device and plug the other one, then it works. No need to reboot.

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.

lsusb output:

$ 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

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

Now here is what appears in /var/log/messages.log when I plug the second USB device (none of that happens if I plug only one of these 2 devices):

$ 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

You might ask what happens in practice?
- when plugged second, the mouse does not work at all (doesn't move the pointer)
- when plugged second, the audio DAC does show up in the sound card list in alsamixer, but when I select it, after 1 second alsamixer complains that it was unplugged.

Thanks
Benoit