Udev rule mistaken identity of ttyUSB device

[Martin Owens]

Binary package hint: udev

Debugging a problem with a cheerled device which uses a 067b:2303 Prolific Technology, Inc. PL2303 Serial Port to communicate. I built a simple module which lets the user update this shop display LED device and it worked well until 10.04

The device is fickle and sending garbage to it does render it's communication inoperable. What I noticed was that the ttyUSB0 device was group own by dialout and I suspect that /lib/udev/rules.d/50-udev-default.rules line 15 was to blame.

I commented it out and the device and scripts now work correctly as expected. Code of script is available here if curious:

https://code.launchpad.net/~doctormo/doctormo-random/cheerled

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: udev 151-12.2 [modified: lib/udev/rules.d/50-udev-default.rules]
ProcVersionSignature: Ubuntu 2.6.32-25.45-generic 2.6.32.21+drm33.7
Uname: Linux 2.6.32-25-generic i686
Architecture: i386
CustomUdevRuleFiles: 10-vboxdrv.rules
Date: Fri Nov 12 15:55:36 2010
MachineType: Dell Inc. Dell DXC051
ProcCmdLine: BOOT_IMAGE=/vmlinuz-2.6.32-25-generic root=UUID=8a298072-6af1-4dd5-abc0-497833b1ef00 ro quiet splash
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: udev
dmi.bios.date: 03/31/2006
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A05
dmi.board.name: 0MF252
dmi.board.vendor: Dell Inc.
dmi.chassis.type: 15
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA05:bd03/31/2006:svnDellInc.:pnDellDXC051:pvr:rvnDellInc.:rn0MF252:rvr:cvnDellInc.:ct15:cvr:
dmi.product.name: Dell DXC051
dmi.sys.vendor: Dell Inc.

[oddvar (aha5262)]

Can confirm this bug 2011-02-19 in Ubuntu 10.10.
I have Pentium D desktop, not laptop. Error message flash over screen at boot, but it boots ok at last
What I have done recently to my system, is I installed from Synaptic several Ubuntu programs to monitor
temperature kernel-i2 sensors.