Score:0

udev does not create symlink

nr flag

I am trying to give my sensor device a static name. I opened a file called 99-usb-serial.rules in /etc/udev/rules.d and wrote the following rule:

KERNEL=="ttyACM0",KERNELS=="1-1",SUBSYSTEM=="tty",SUBSYSTEMS=="usb",ATTRS{idVendor}=="108c", ATTRS{idProduct}=="017b", SYMLINK+="/dev/mydevice"

This does not create any symlink in /dev. To check whether my command is correct or not,

Command:

udevadm -info --name/dev/ttyACM0 --atribute-walk

output:

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/pci0000:00/0000:00:14.0/usb1/1-1/1-1:1.0/tty/ttyACM0':
    KERNEL=="ttyACM0"
    SUBSYSTEM=="tty"
    DRIVER==""

  looking at parent device '/devices/pci0000:00/0000:00:14.0/usb1/1-1/1-1:1.0':
    KERNELS=="1-1:1.0"
    SUBSYSTEMS=="usb"
    DRIVERS=="cdc_acm"
    ATTRS{authorized}=="1"
    ATTRS{bInterfaceSubClass}=="02"
    ATTRS{bInterfaceNumber}=="00"
    ATTRS{bmCapabilities}=="2"
    ATTRS{bInterfaceClass}=="02"
    ATTRS{bNumEndpoints}=="01"
    ATTRS{bInterfaceProtocol}=="00"
    ATTRS{supports_autosuspend}=="1"
    ATTRS{bAlternateSetting}==" 0"

  looking at parent device '/devices/pci0000:00/0000:00:14.0/usb1/1-1':
    KERNELS=="1-1"
    SUBSYSTEMS=="usb"
    DRIVERS=="usb"
    ATTRS{version}==" 2.00"
    ATTRS{devpath}=="1"
    ATTRS{bConfigurationValue}=="1"
    ATTRS{product}=="XDK Application"
    ATTRS{devnum}=="21"
    ATTRS{bDeviceProtocol}=="00"
    ATTRS{manufacturer}=="Bosch Connected Devices and Solutions GmbH"
    ATTRS{busnum}=="1"
    ATTRS{rx_lanes}=="1"
    ATTRS{tx_lanes}=="1"
    ATTRS{ltm_capable}=="no"
    ATTRS{serial}=="2496B4065B328D1E"
    ATTRS{bDeviceClass}=="02"
    ATTRS{bNumConfigurations}=="1"
    ATTRS{bMaxPacketSize0}=="64"
    ATTRS{bMaxPower}=="500mA"
    ATTRS{bmAttributes}=="c0"
    ATTRS{urbnum}=="13"
    ATTRS{avoid_reset_quirk}=="0"
    ATTRS{bNumInterfaces}==" 2"
    ATTRS{bcdDevice}=="0000"
    ATTRS{idProduct}=="017b"
    ATTRS{authorized}=="1"
    ATTRS{bDeviceSubClass}=="00"
    ATTRS{configuration}==""
    ATTRS{removable}=="removable"
    ATTRS{idVendor}=="108c"
    ATTRS{maxchild}=="0"
    ATTRS{speed}=="12"
    ATTRS{quirks}=="0x0"

  looking at parent device '/devices/pci0000:00/0000:00:14.0/usb1':
    KERNELS=="usb1"
    SUBSYSTEMS=="usb"
    DRIVERS=="usb"
    ATTRS{serial}=="0000:00:14.0"
    ATTRS{bNumInterfaces}==" 1"
    ATTRS{urbnum}=="577"
    ATTRS{version}==" 2.00"
    ATTRS{quirks}=="0x0"
    ATTRS{bcdDevice}=="0513"
    ATTRS{authorized_default}=="1"
    ATTRS{product}=="xHCI Host Controller"
    ATTRS{bConfigurationValue}=="1"
    ATTRS{devnum}=="1"
    ATTRS{avoid_reset_quirk}=="0"
    ATTRS{removable}=="unknown"
    ATTRS{interface_authorized_default}=="1"
    ATTRS{tx_lanes}=="1"
    ATTRS{configuration}==""
    ATTRS{busnum}=="1"
    ATTRS{speed}=="480"
    ATTRS{rx_lanes}=="1"
    ATTRS{bNumConfigurations}=="1"
    ATTRS{maxchild}=="12"
    ATTRS{devpath}=="0"
    ATTRS{bDeviceProtocol}=="01"
    ATTRS{bMaxPacketSize0}=="64"
    ATTRS{idVendor}=="1d6b"
    ATTRS{idProduct}=="0002"
    ATTRS{bmAttributes}=="e0"
    ATTRS{bMaxPower}=="0mA"
    ATTRS{ltm_capable}=="no"
    ATTRS{authorized}=="1"
    ATTRS{bDeviceSubClass}=="00"
    ATTRS{manufacturer}=="Linux 5.13.0-28-generic xhci-hcd"
    ATTRS{bDeviceClass}=="09"

  looking at parent device '/devices/pci0000:00/0000:00:14.0':
    KERNELS=="0000:00:14.0"
    SUBSYSTEMS=="pci"
    DRIVERS=="xhci_hcd"
    ATTRS{local_cpulist}=="0-3"
    ATTRS{driver_override}=="(null)"
    ATTRS{broken_parity_status}=="0"
    ATTRS{dbc}=="disabled"
    ATTRS{dma_mask_bits}=="64"
    ATTRS{d3cold_allowed}=="1"
    ATTRS{class}=="0x0c0330"
    ATTRS{enable}=="1"
    ATTRS{vendor}=="0x8086"
    ATTRS{revision}=="0x21"
    ATTRS{msi_bus}=="1"
    ATTRS{irq}=="125"
    ATTRS{subsystem_vendor}=="0x1043"
    ATTRS{power_state}=="D0"
    ATTRS{device}=="0x9d2f"
    ATTRS{ari_enabled}=="0"
    ATTRS{numa_node}=="-1"
    ATTRS{subsystem_device}=="0x201f"
    ATTRS{consistent_dma_mask_bits}=="64"
    ATTRS{local_cpus}=="f"

  looking at parent device '/devices/pci0000:00':
    KERNELS=="pci0000:00"
    SUBSYSTEMS==""
    DRIVERS==""
    ATTRS{waiting_for_supplier}=="0"

To debug the problem, I used udevadam test Command:

sudo control --reload-rules --log-priority=debug && udevadm trigger
sudo udevadm test  $(udevadm info -q path -n /dev/ttyACM0)

output:

This program is for debugging only, it does not run any program
specified by a RUN key. It may show incorrect results, because
some values may be different, or not available at a simulation run.

Load module index
Parsed configuration file /usr/lib/systemd/network/99-default.link
Parsed configuration file /usr/lib/systemd/network/73-usb-net-by-mac.link
Created link configuration context.
Reading rules file: /usr/lib/udev/rules.d/39-usbmuxd.rules
Reading rules file: /usr/lib/udev/rules.d/40-usb-media-players.rules
Reading rules file: /usr/lib/udev/rules.d/40-usb_modeswitch.rules
Reading rules file: /usr/lib/udev/rules.d/40-vm-hotadd.rules
Reading rules file: /usr/lib/udev/rules.d/50-apport.rules
Reading rules file: /usr/lib/udev/rules.d/50-firmware.rules
Reading rules file: /usr/lib/udev/rules.d/50-udev-default.rules
Reading rules file: /usr/lib/udev/rules.d/55-dm.rules
Reading rules file: /usr/lib/udev/rules.d/55-ippusbxd.rules
Reading rules file: /usr/lib/udev/rules.d/56-hpmud.rules
Reading rules file: /usr/lib/udev/rules.d/60-autosuspend-chromiumos.rules
Reading rules file: /usr/lib/udev/rules.d/60-block.rules
Reading rules file: /usr/lib/udev/rules.d/60-cdrom_id.rules
Reading rules file: /usr/lib/udev/rules.d/60-crda.rules
Reading rules file: /usr/lib/udev/rules.d/60-drm.rules
Reading rules file: /usr/lib/udev/rules.d/60-evdev.rules
Reading rules file: /usr/lib/udev/rules.d/60-fido-id.rules
Reading rules file: /usr/lib/udev/rules.d/60-input-id.rules
Reading rules file: /usr/lib/udev/rules.d/60-inputattach.rules
Reading rules file: /usr/lib/udev/rules.d/60-libfprint-2.rules
Reading rules file: /usr/lib/udev/rules.d/60-libgphoto2-6.rules
Reading rules file: /usr/lib/udev/rules.d/60-libsane.rules
Reading rules file: /usr/lib/udev/rules.d/60-pcmcia.rules
Reading rules file: /usr/lib/udev/rules.d/60-persistent-alsa.rules
Reading rules file: /usr/lib/udev/rules.d/60-persistent-input.rules
Reading rules file: /usr/lib/udev/rules.d/60-persistent-storage-dm.rules
Reading rules file: /usr/lib/udev/rules.d/60-persistent-storage-tape.rules
Reading rules file: /usr/lib/udev/rules.d/60-persistent-storage.rules
Reading rules file: /usr/lib/udev/rules.d/60-persistent-v4l.rules
Reading rules file: /usr/lib/udev/rules.d/60-sensor.rules
Reading rules file: /usr/lib/udev/rules.d/60-serial.rules
Reading rules file: /usr/lib/udev/rules.d/60-tpm-udev.rules
Reading rules file: /usr/lib/udev/rules.d/61-autosuspend-manual.rules
Reading rules file: /usr/lib/udev/rules.d/61-gdm.rules
Reading rules file: /usr/lib/udev/rules.d/61-gnome-settings-daemon-rfkill.rules
Reading rules file: /usr/lib/udev/rules.d/61-persistent-storage-android.rules
Reading rules file: /usr/lib/udev/rules.d/64-btrfs.rules
Reading rules file: /usr/lib/udev/rules.d/64-xorg-xkb.rules
Reading rules file: /usr/lib/udev/rules.d/65-libwacom.rules
Reading rules file: /usr/lib/udev/rules.d/66-snapd-autoimport.rules
Reading rules file: /usr/lib/udev/rules.d/69-cd-sensors.rules
Reading rules file: /usr/lib/udev/rules.d/69-libmtp.rules
Reading rules file: /usr/lib/udev/rules.d/69-wacom.rules
Reading rules file: /usr/lib/udev/rules.d/70-joystick.rules
Reading rules file: /usr/lib/udev/rules.d/70-mouse.rules
Reading rules file: /usr/lib/udev/rules.d/70-power-switch.rules
Reading rules file: /usr/lib/udev/rules.d/70-printers.rules
Reading rules file: /etc/udev/rules.d/70-snap.snap-store.rules
Reading rules file: /etc/udev/rules.d/70-snap.snapd.rules
Reading rules file: /usr/lib/udev/rules.d/70-spice-vdagentd.rules
Reading rules file: /usr/lib/udev/rules.d/70-touchpad.rules
Reading rules file: /usr/lib/udev/rules.d/70-u2f.rules
Reading rules file: /usr/lib/udev/rules.d/70-uaccess.rules
Reading rules file: /usr/lib/udev/rules.d/71-nvidia.rules
Reading rules file: /usr/lib/udev/rules.d/71-power-switch-proliant.rules
Reading rules file: /usr/lib/udev/rules.d/71-seat.rules
Reading rules file: /usr/lib/udev/rules.d/71-u-d-c-gpu-detection.rules
Reading rules file: /usr/lib/udev/rules.d/73-seat-late.rules
Reading rules file: /usr/lib/udev/rules.d/73-special-net-names.rules
Reading rules file: /usr/lib/udev/rules.d/75-net-description.rules
Reading rules file: /usr/lib/udev/rules.d/75-probe_mtd.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-cinterion-port-types.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-dell-port-types.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-dlink-port-types.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-ericsson-mbm.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-fibocom-port-types.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-haier-port-types.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-huawei-net-port-types.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-longcheer-port-types.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-mtk-port-types.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-nokia-port-types.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-pcmcia-device-blacklist.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-qdl-device-blacklist.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-quectel-port-types.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-sierra.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-simtech-port-types.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-telit-port-types.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-tplink-port-types.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-ublox-port-types.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-usb-device-blacklist.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-usb-serial-adapters-greylist.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-x22x-port-types.rules
Reading rules file: /usr/lib/udev/rules.d/77-mm-zte-port-types.rules
Reading rules file: /usr/lib/udev/rules.d/78-graphics-card.rules
Reading rules file: /usr/lib/udev/rules.d/78-sound-card.rules
Reading rules file: /usr/lib/udev/rules.d/80-debian-compat.rules
Reading rules file: /usr/lib/udev/rules.d/80-drivers.rules
Reading rules file: /usr/lib/udev/rules.d/80-iio-sensor-proxy.rules
Reading rules file: /usr/lib/udev/rules.d/80-libinput-device-groups.rules
Reading rules file: /usr/lib/udev/rules.d/80-mm-candidate.rules
Reading rules file: /usr/lib/udev/rules.d/80-net-setup-link.rules
Reading rules file: /usr/lib/udev/rules.d/80-udisks2.rules
Reading rules file: /usr/lib/udev/rules.d/81-net-dhcp.rules
Reading rules file: /usr/lib/udev/rules.d/84-nm-drivers.rules
Reading rules file: /usr/lib/udev/rules.d/85-brltty.rules
Reading rules file: /usr/lib/udev/rules.d/85-hdparm.rules
Reading rules file: /usr/lib/udev/rules.d/85-hplj10xx.rules
Reading rules file: /usr/lib/udev/rules.d/85-nm-unmanaged.rules
Reading rules file: /usr/lib/udev/rules.d/85-regulatory.rules
Reading rules file: /usr/lib/udev/rules.d/90-alsa-restore.rules
Reading rules file: /usr/lib/udev/rules.d/90-bolt.rules
Reading rules file: /usr/lib/udev/rules.d/90-console-setup.rules
Reading rules file: /usr/lib/udev/rules.d/90-fwupd-devices.rules
Reading rules file: /usr/lib/udev/rules.d/90-libgpod.rules
Reading rules file: /usr/lib/udev/rules.d/90-libinput-fuzz-override.rules
Reading rules file: /usr/lib/udev/rules.d/90-nm-thunderbolt.rules
Reading rules file: /usr/lib/udev/rules.d/90-pulseaudio.rules
Reading rules file: /usr/lib/udev/rules.d/95-cd-devices.rules
Reading rules file: /usr/lib/udev/rules.d/95-dm-notify.rules
Reading rules file: /usr/lib/udev/rules.d/95-upower-csr.rules
Reading rules file: /usr/lib/udev/rules.d/95-upower-hid.rules
Reading rules file: /usr/lib/udev/rules.d/95-upower-hidpp.rules
Reading rules file: /usr/lib/udev/rules.d/95-upower-wup.rules
Reading rules file: /usr/lib/udev/rules.d/96-e2scrub.rules
Reading rules file: /usr/lib/udev/rules.d/97-hid2hci.rules
Reading rules file: /usr/lib/udev/rules.d/99-systemd.rules
Configuration file /etc/udev/rules.d/99-usb-serial.rules is marked world-writable. Please remove world writability permission bits. Proceeding anyway.
Reading rules file: /etc/udev/rules.d/99-usb-serial.rules
Invalid inotify descriptor.
DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-1/1-1:1.0/tty/ttyACM0
DEVNAME=/dev/ttyACM0
MAJOR=166
MINOR=0
ACTION=add
SUBSYSTEM=tty
ID_BUS=usb
ID_VENDOR_ID=108c
ID_MODEL_ID=017b
ID_PCI_CLASS_FROM_DATABASE=Serial bus controller
ID_PCI_SUBCLASS_FROM_DATABASE=USB controller
ID_PCI_INTERFACE_FROM_DATABASE=XHCI
ID_VENDOR_FROM_DATABASE=Robert Bosch GmbH
ID_MODEL_FROM_DATABASE=Sunrise Point-LP USB 3.0 xHCI Controller
ID_VENDOR=Bosch_Connected_Devices_and_Solutions_GmbH
ID_VENDOR_ENC=Bosch\x20Connected\x20Devices\x20and\x20Solutions\x20GmbH
ID_MODEL=XDK_Application
ID_MODEL_ENC=XDK\x20Application
ID_REVISION=0000
ID_SERIAL=Bosch_Connected_Devices_and_Solutions_GmbH_XDK_Application_2496B4065B328D1E
ID_SERIAL_SHORT=2496B4065B328D1E
ID_TYPE=generic
ID_USB_INTERFACES=:020200:0a0000:
ID_USB_INTERFACE_NUM=00
ID_USB_DRIVER=cdc_acm
ID_USB_CLASS_FROM_DATABASE=Communications
ID_PATH=pci-0000:00:14.0-usb-0:1:1.0
ID_PATH_TAG=pci-0000_00_14_0-usb-0_1_1_0
DEVLINKS=/dev/serial/by-path/pci-0000:00:14.0-usb-0:1:1.0 /dev/serial/by-id/usb-Bosch_Connected_Devices_and_Solutions_GmbH_XDK_Application_2496B4065B328D1E-if00 /dev//dev/mydevice
ID_MM_CANDIDATE=1
TAGS=:systemd:
USEC_INITIALIZED=6250133716
Unload module index
Unloaded link configuration context.

Problem seems to be here I guess:

Reading rules file: /etc/udev/rules.d/99-usb-serial.rules
Invalid inotify descriptor

But I don't know how to fix this. The other answers does not seems to be helpfull.

Score:0
in flag

The Rules should be :

KERNEL=="ttyACM*", ... , SYMLINK+="ttyUSB%n", MODE:="0666"

Hope this helps.

Score:0
nr flag

The simlink was created but it was creating another dev folder in the dev because of this:SYMLINK+="/dev/mydevice"

so just removing the /dev from SYMLINK creates symlink in the dev SYMLINK+="mydevice"

mangohost

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