/dev/lcd* device name is not predictable between boots

[Bengt Nilsson]

I am using an imonlcd device in Ubuntu Studio 13.04.
My hardware is a Gigabyte GA-880GMA-UD2H with a Athlon X2, in an Antec Veris box.

After upgrading from 12.04 to 13.04 I found that the imonlcd function was unreliable, and the reason was that the device name /dev/lcd* was sometimes not the same as referred to in the LCDd.conf. Sometimes it was /dev/lcd0, sometimes /dev/lcd1.

The imonlcd device name needs to be predictable and stable for lcdproc to work.

lsb_release -rd
Description: Ubuntu 13.04
Release: 13.04

apt-cache policy lcdproc
lcdproc:
  Installerad: 0.5.5-2
  Kandidat: 0.5.5-2
  Versionstabell:
 *** 0.5.5-2 0
        500 http://se.archive.ubuntu.com/ubuntu/ raring/universe amd64 Packages
        100 /var/lib/dpkg/status

What I expect: I want to turn off the IMON LCD backlight at boot
What happens: It sometimes does not do that.

[Bengt Nilsson (bnilsson11)]

To clarify: /dev/lcd* device name changes in between boots.

If I do "ls /dev" to find the current lcd device name after the last boot, update the /etc/LCDd.conf to match, and then do "/etc/init.d/LCDd restart" it works fine.

[Bengt Nilsson (bnilsson11)]

To clarify further:

I have set /etc/LCDd.conf to turn off my imonlcd backlight at boot.

When it does not do that, I check what device name (/dev/lcd0 or /dev/lcd1) I have this time, and it is then always different than what I assigned in LCDd.conf. If I then modify the imonlcd device entry in /etc/LCDd.conf to the current device name and then restart LCDd by "/etc/init.d/LCDd restart" the imonlcd backlight turns off as it should.

I am pretty sure now that the the device name toggles between /dev/lcd0 and /dev/lcd1 between boots.

[Bengt Nilsson (bnilsson11)]

To clarify further: This problem first appeared for me when I installed Ubuntu 13.04, I did not experience this in earlier releases.

[Niki Iv (niki-iv)]

I am experiencing the exact same problem
Kernel is 3.8.0-33-generic from Ubuntu 12.04.04

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Bengt Nilsson (bnilsson11)]

This bug is still present in Ubuntu Studio 14.04 LTS Trusty Tahr.

[Rob Battie (duncanrix)]

I also have this issue with 14.04