USB input device interfaces compete for the same symlink name in 60-persistent-input.rules
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
udev (Ubuntu) |
Fix Released
|
High
|
Martin Pitt | ||
Precise |
Fix Released
|
Undecided
|
Unassigned | ||
Quantal |
Fix Released
|
High
|
Martin Pitt |
Bug Description
The current rules in 60-persistent-
These are the problematic rules:
KERNEL=
KERNEL=="event*", ENV{ID_BUS}=="?*", ENV{.INPUT_
The above rules can be matched by multiple devices if a USB input device has multiple USB interfaces (such as the Microsoft Wired Keyboard 600, which has two keyboard interfaces). Because the generated symlink names do not include the USB interface number, the multiple devices will compete over the same symlink name. According to the udev man page, the device that wins is undefined unless the devices are assigned different link_priority values (which they are not).
There are other rules in 60-persistent-
It seems like the correct fix is to give interface 0 a higher link_priority value than the other interfaces. This would guarantee that interface 0 always wins the competition.
[1] http://
[2] http://
$ lsb_release -rd
Description: Ubuntu 12.04.1 LTS
Release: 12.04
$ apt-cache policy udev
udev:
Installed: 175-0ubuntu9.1
Candidate: 175-0ubuntu9.1
Version table:
*** 175-0ubuntu9.1 0
500 http://
100 /var/lib/
175-0ubuntu9 0
500 http://
tags: | added: rls-q-incoming |
Changed in udev (Ubuntu): | |
importance: | Undecided → High |
I'm attaching a debdiff for Quantal that contains a patch for this bug. This version has been uploaded to my PPA (<https:/ /launchpad. net/~a7x/ +archive/ bug1057824>) and will be done building in a few hours. To install:
sudo apt-add-repository ppa:a7x/bug1057824
sudo apt-get update
sudo apt-get upgrade