Table of Contents
PLD udev FAQ (udev-0.71-5)
From: Fryderyk Dziarmagowski <freetz> To: pld-users-pl@lists.pld-linux.org Subject: [FAQ] PLD udev FAQ Date: Sun, 6 Nov 2005 21:59:31 +0100 X-Translated-By: Michał Łukaszek <prism>
Which kernel version is recommended for proper work of udev/udev-hotplug?
Minimum recommended version is 2.6.12.x (udev
hotplug
won't work with the older)
Udev doesn't load all modules
That's because it loads only modules for PCI devices that meet the requirements included in udev rules. That rules allow auto-loading feature only for internal USB devices (hubs), such as uhci-hcd
or ehci-hcd
.
If you want to get the modules of all devices loaded automatically, enable udevsynthetize
in /etc/udev/udev.conf
. This is experimental and not fully tested though.
What about hotplug? Will my pendrive work?
hotplug
included in current udev replaces the old hotplug
completely. Parallel work of both is not recommended, so after udev
is installed the old hotplug
package is removed.
USB pendrives will work like a charm if you read answer no. 1.
I'd like to connect my digital camera/scanner/other USB device to my computer. Do I have to mount /proc/bus/usb with proper permissions?
Absolutely not. Install udev-digicam
package, add yourself to the digicam group, and udev
's agent will do the rest, no matter if the device is a scanner or another USB input device.
Can udev automatically mount partitions or cd drives it finds?
While technically possible, udev
is not designed to manage your /etc/fstab entries. There are specialized programs for this, like gnome-volume-manager
.
I'm using nvidia-legacy and the /dev/nvidia* is not created!
That's a problem of nvidia
(legacy) drivers. udev
has nothing to do with it. Unfortunately, you must manually create proper device files using mknod
.
You can make modprobe
create these devices for you every time the nvidia
module is loaded by adding the following line to your /etc/modprobe.conf:
install nvidia /sbin/modprobe --ignore-install nvidia && { mknod /dev/nvidia0 c 195 0; mknod /dev/nvidia1 c 195 1; mknod /dev/nvidia2 c 195 2; mknod /dev/nvidia3 c 195 3; mknod /dev/nvidiactl c 195 255; /bin/true; }
Note that this should be all in one line.
Modules like psmouse and evdev are not loaded automatically
The kernel's input layer is broken. It's said to be fixed in 2.6.15.
Do I have to add the usb-controller alias in /etc/modprobe.conf?
No. All *-hcd
modules are loaded automatically.
I get the error messages about failed agents in my system logs
They don't work because they are not there - unless you installed udev-digicam
, which has the usb agent. That udev warnings in logs don't look nice, but they are absolutely harmless. This will be fixed if there is a person willing to fix it.
I've got a problem that is not covered here. How do I diagnose it?
Try the following:
- set
udev_log
toinfo
in /etc/udev/udev.conf to improve verbosity ofudev
; - use
udevmonitor
(seeman udevmonitor
) to get even more infomation from older udev; - use
udevadm monitor
(see 'man udevadm') to get even more infomation (udev-151) ; - check the linux-hotplug list's archive at http://marc.theaimsgroup.com/?l=linux-hotplug-devel.
How can I increase udev logs verbosity
Try (udev-154):
udevadm control --log-priority=debug
And check results in '/var/log/daemon'
How to test rule I have just written?
Reload rules:
udevadm control --reload-rules # (udev-151)
Trigger event (replug device) or trigger all events:
udevadm trigger --verbose
If still unsure, ask your question on PLD mailing lists.