Udev rule doesn't work, why?

Question

My udev rule is not working. I've added information about the udev rule:

udev rule:

$ cat /lib/udev/rules.d/95-monitor.rules 
KERNEL=="card0", SUBSYSTEM=="drm", RUN+="/bin/bash /home/koko/Desktop/monitor.sh"

executed:

sudo udevadm control --reload
sudo udevadm trigger

monitor.sh

#!/bin/bash
notify-send "Monitor Connected."

Udev is running:

$ service --status-all
..
[ + ]  udev
..

udev info

$ sudo udevadm info -a -p /devices/pci00:00/0000:00:02.0/drm/card0

Udevadm info starts with the device specified by the devpath and then
walks up the chain of parent devices. It prints for every device
found, all possible attributes in the udev rules key format.
A rule to match, can be composed by the attributes of the device
and the attributes from one single parent device.

  looking at device '/devices/pci0000:00/0000:00:02.0/drm/card0':
    KERNEL=="card0"
    SUBSYSTEM=="drm"
    DRIVER==""
    ATTR{error}=="no error state collected"

  looking at parent device '/devices/pci0000:00/0000:00:02.0':
    KERNELS=="0000:00:02.0"
    SUBSYSTEMS=="pci"
    DRIVERS=="i915"
    ATTRS{boot_vga}=="1"
    ATTRS{broken_parity_status}=="0"
    ATTRS{class}=="0x030000"
    ATTRS{consistent_dma_mask_bits}=="36"
    ATTRS{d3cold_allowed}=="1"
    ATTRS{device}=="0x0046"
    ATTRS{dma_mask_bits}=="36"
    ATTRS{driver_override}=="(null)"
    ATTRS{enable}=="1"
    ATTRS{irq}=="26"
    ATTRS{local_cpulist}=="0-3"
    ATTRS{local_cpus}=="0f"
    ATTRS{msi_bus}=="1"
    ATTRS{numa_node}=="-1"
    ATTRS{subsystem_device}=="0x0410"
    ATTRS{subsystem_vendor}=="0x1028"
    ATTRS{vendor}=="0x8086"

  looking at parent device '/devices/pci0000:00':
    KERNELS=="pci0000:00"
    SUBSYSTEMS==""
    DRIVERS==""

udevadm monitor:

$ sudo udevadm monitor --environment --udev
monitor will print the received events for:
UDEV - the event which udev sends out after rule processing

UDEV  [26447.971745] change   /devices/pci0000:00/0000:00:02.0/drm/card0 (drm)
ACTION=change
DEVNAME=/dev/dri/card0
DEVPATH=/devices/pci0000:00/0000:00:02.0/drm/card0
DEVTYPE=drm_minor
HOTPLUG=1
ID_FOR_SEAT=drm-pci-0000_00_02_0
ID_PATH=pci-0000:00:02.0
ID_PATH_TAG=pci-0000_00_02_0
MAJOR=226
MINOR=0
SEQNUM=3035
SUBSYSTEM=drm
TAGS=:uaccess:master-of-seat:seat:
USEC_INITIALIZED=21623159

In general, don't expect to be able to desktop-ish things from `RUN` (because the programs are started by the kernel as root in a restricted environment). I don't know in detail how `notify-send` works, but this may be the problem. Try appending to a file in `/tmp` or a named pipe while inside `RUN` instead, and use `inotify` etc. if you want messages. If a udev rule needs to interact with the user, re-think your approach - it's probably wrong, that's not what the rules are for. — dirkt, Aug 10 '17 at 12:25

Udev rule doesn't work, why?

0 Answers0