The udev rule I defined isn't applied until a bluetooth device is disconnected

Hello, everyone. I’m basically trying to invoke a script every time a bluetooth device is connected. Here is what I did so far.

I created a bluetooth.rules file in /etc/udev/rules.d which contains only one line:

SUBSYSTEM=="bluetooth", RUN+="/path/to/my/script"

The problem is that the script is only invoked when the device is disconnected from the system but never at the moment the connection was formed.

This is udevadm monitor’s output at the point the device is connected (after I ran bluetoothctl connect <MAC address> from the command line:

KERNEL[71481.889315] add      /devices/pci0000:00/0000:00:14.0/usb3/3-11/3-11:1.0/bluetooth/hci0/hci0:256 (bluetooth)
UDEV  [71481.903034] add      /devices/pci0000:00/0000:00:14.0/usb3/3-11/3-11:1.0/bluetooth/hci0/hci0:256 (bluetooth)
KERNEL[71482.495175] add      /devices/virtual/input/input45 (input)
KERNEL[71482.495248] add      /devices/virtual/input/input45/event24 (input)
UDEV  [71482.496423] add      /devices/virtual/input/input45 (input)
UDEV  [71482.591539] add      /devices/virtual/input/input45/event24 (input)

And at the moment the device was disconnected:

KERNEL[71553.849145] remove   /devices/virtual/input/input45/event24 (input)
UDEV  [71553.850872] remove   /devices/virtual/input/input45/event24 (input)
KERNEL[71553.919022] remove   /devices/virtual/input/input45 (input)
UDEV  [71553.919624] remove   /devices/virtual/input/input45 (input)
KERNEL[71556.168971] remove   /devices/pci0000:00/0000:00:14.0/usb3/3-11/3-11:1.0/bluetooth/hci0/hci0:256 (bluetooth)
UDEV  [71556.179602] remove   /devices/pci0000:00/0000:00:14.0/usb3/3-11/3-11:1.0/bluetooth/hci0/hci0:256 (bluetooth)

Here is the result after running udevadm info --attribute-walk --path:

$ udevadm info --attribute-walk --path=/devices/pci0000:00/0000:00:14.0/usb3/3-11/3-11:1.0/bluetooth/hci0/hci0:256

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/usb3/3-11/3-11:1.0/bluetooth/hci0/hci0:256':
    KERNEL=="hci0:256"
    SUBSYSTEM=="bluetooth"
    DRIVER==""
    ATTR{power/control}=="auto"
    ATTR{power/runtime_active_time}=="0"
    ATTR{power/runtime_status}=="unsupported"
    ATTR{power/runtime_suspended_time}=="0"

  looking at parent device '/devices/pci0000:00/0000:00:14.0/usb3/3-11/3-11:1.0/bluetooth/hci0':
    KERNELS=="hci0"
    SUBSYSTEMS=="bluetooth"
    DRIVERS==""
    ATTRS{power/control}=="auto"
    ATTRS{power/runtime_active_time}=="0"
    ATTRS{power/runtime_status}=="unsupported"
    ATTRS{power/runtime_suspended_time}=="0"

  looking at parent device '/devices/pci0000:00/0000:00:14.0/usb3/3-11/3-11:1.0':
    KERNELS=="3-11:1.0"
    SUBSYSTEMS=="usb"
    DRIVERS=="btusb"
    ATTRS{authorized}=="1"
    ATTRS{bAlternateSetting}==" 0"
    ATTRS{bInterfaceClass}=="e0"
    ATTRS{bInterfaceNumber}=="00"
    ATTRS{bInterfaceProtocol}=="01"
    ATTRS{bInterfaceSubClass}=="01"
    ATTRS{bNumEndpoints}=="03"
    ATTRS{supports_autosuspend}=="1"

  looking at parent device '/devices/pci0000:00/0000:00:14.0/usb3/3-11':
    KERNELS=="3-11"
    SUBSYSTEMS=="usb"
    DRIVERS=="usb"
    ATTRS{authorized}=="1"
    ATTRS{avoid_reset_quirk}=="0"
    ATTRS{bConfigurationValue}=="1"
    ATTRS{bDeviceClass}=="e0"
    ATTRS{bDeviceProtocol}=="01"
    ATTRS{bDeviceSubClass}=="01"
    ATTRS{bMaxPacketSize0}=="64"
    ATTRS{bMaxPower}=="100mA"
    ATTRS{bNumConfigurations}=="1"
    ATTRS{bNumInterfaces}==" 2"
    ATTRS{bcdDevice}=="0001"
    ATTRS{bmAttributes}=="e0"
    ATTRS{busnum}=="3"
    ATTRS{configuration}==""
    ATTRS{devnum}=="6"
    ATTRS{devpath}=="11"
    ATTRS{idProduct}=="07dc"
    ATTRS{idVendor}=="8087"
    ATTRS{ltm_capable}=="no"
    ATTRS{maxchild}=="0"
    ATTRS{power/active_duration}=="63390"
    ATTRS{power/autosuspend}=="2"
    ATTRS{power/autosuspend_delay_ms}=="2000"
    ATTRS{power/connected_duration}=="327300"
    ATTRS{power/control}=="auto"
    ATTRS{power/level}=="auto"
    ATTRS{power/persist}=="1"
    ATTRS{power/runtime_active_time}=="63920"
    ATTRS{power/runtime_status}=="suspended"
    ATTRS{power/runtime_suspended_time}=="263050"
    ATTRS{power/wakeup}=="disabled"
    ATTRS{power/wakeup_abort_count}==""
    ATTRS{power/wakeup_active}==""
    ATTRS{power/wakeup_active_count}==""
    ATTRS{power/wakeup_count}==""
    ATTRS{power/wakeup_expire_count}==""
    ATTRS{power/wakeup_last_time_ms}==""
    ATTRS{power/wakeup_max_time_ms}==""
    ATTRS{power/wakeup_total_time_ms}==""
    ATTRS{quirks}=="0x0"
    ATTRS{removable}=="fixed"
    ATTRS{remove}=="(not readable)"
    ATTRS{rx_lanes}=="1"
    ATTRS{speed}=="12"
    ATTRS{tx_lanes}=="1"
    ATTRS{urbnum}=="1227"
    ATTRS{version}==" 2.00"

  looking at parent device '/devices/pci0000:00/0000:00:14.0/usb3':
    KERNELS=="usb3"
    SUBSYSTEMS=="usb"
    DRIVERS=="usb"
    ATTRS{authorized}=="1"
    ATTRS{authorized_default}=="1"
    ATTRS{avoid_reset_quirk}=="0"
    ATTRS{bConfigurationValue}=="1"
    ATTRS{bDeviceClass}=="09"
    ATTRS{bDeviceProtocol}=="01"
    ATTRS{bDeviceSubClass}=="00"
    ATTRS{bMaxPacketSize0}=="64"
    ATTRS{bMaxPower}=="0mA"
    ATTRS{bNumConfigurations}=="1"
    ATTRS{bNumInterfaces}==" 1"
    ATTRS{bcdDevice}=="0515"
    ATTRS{bmAttributes}=="e0"
    ATTRS{busnum}=="3"
    ATTRS{configuration}==""
    ATTRS{devnum}=="1"
    ATTRS{devpath}=="0"
    ATTRS{idProduct}=="0002"
    ATTRS{idVendor}=="1d6b"
    ATTRS{interface_authorized_default}=="1"
    ATTRS{ltm_capable}=="no"
    ATTRS{manufacturer}=="Linux 5.15.68-1-lts xhci-hcd"
    ATTRS{maxchild}=="15"
    ATTRS{power/active_duration}=="1310670"
    ATTRS{power/autosuspend}=="0"
    ATTRS{power/autosuspend_delay_ms}=="0"
    ATTRS{power/connected_duration}=="71736870"
    ATTRS{power/control}=="auto"
    ATTRS{power/level}=="auto"
    ATTRS{power/runtime_active_time}=="1309771"
    ATTRS{power/runtime_status}=="suspended"
    ATTRS{power/runtime_suspended_time}=="70427094"
    ATTRS{power/wakeup}=="disabled"
    ATTRS{power/wakeup_abort_count}==""
    ATTRS{power/wakeup_active}==""
    ATTRS{power/wakeup_active_count}==""
    ATTRS{power/wakeup_count}==""
    ATTRS{power/wakeup_expire_count}==""
    ATTRS{power/wakeup_last_time_ms}==""
    ATTRS{power/wakeup_max_time_ms}==""
    ATTRS{power/wakeup_total_time_ms}==""
    ATTRS{product}=="xHCI Host Controller"
    ATTRS{quirks}=="0x0"
    ATTRS{removable}=="unknown"
    ATTRS{remove}=="(not readable)"
    ATTRS{rx_lanes}=="1"
    ATTRS{serial}=="0000:00:14.0"
    ATTRS{speed}=="480"
    ATTRS{tx_lanes}=="1"
    ATTRS{urbnum}=="4538"
    ATTRS{version}==" 2.00"

  looking at parent device '/devices/pci0000:00/0000:00:14.0':
    KERNELS=="0000:00:14.0"
    SUBSYSTEMS=="pci"
    DRIVERS=="xhci_hcd"
    ATTRS{ari_enabled}=="0"
    ATTRS{broken_parity_status}=="0"
    ATTRS{class}=="0x0c0330"
    ATTRS{consistent_dma_mask_bits}=="64"
    ATTRS{d3cold_allowed}=="1"
    ATTRS{device}=="0x8c31"
    ATTRS{dma_mask_bits}=="64"
    ATTRS{driver_override}=="(null)"
    ATTRS{enable}=="1"
    ATTRS{irq}=="30"
    ATTRS{local_cpulist}=="0-7"
    ATTRS{local_cpus}=="ff"
    ATTRS{msi_bus}=="1"
    ATTRS{msi_irqs/30}=="msi"
    ATTRS{numa_node}=="-1"
    ATTRS{power/control}=="on"
    ATTRS{power/runtime_active_time}=="71737713"
    ATTRS{power/runtime_status}=="active"
    ATTRS{power/runtime_suspended_time}=="0"
    ATTRS{power/wakeup}=="enabled"
    ATTRS{power/wakeup_abort_count}=="0"
    ATTRS{power/wakeup_active}=="0"
    ATTRS{power/wakeup_active_count}=="0"
    ATTRS{power/wakeup_count}=="0"
    ATTRS{power/wakeup_expire_count}=="0"
    ATTRS{power/wakeup_last_time_ms}=="0"
    ATTRS{power/wakeup_max_time_ms}=="0"
    ATTRS{power/wakeup_total_time_ms}=="0"
    ATTRS{power_state}=="D0"
    ATTRS{remove}=="(not readable)"
    ATTRS{rescan}=="(not readable)"
    ATTRS{resource0}=="(not readable)"
    ATTRS{revision}=="0x04"
    ATTRS{subsystem_device}=="0x2211"
    ATTRS{subsystem_vendor}=="0x17aa"
    ATTRS{vendor}=="0x8086"

  looking at parent device '/devices/pci0000:00':
    KERNELS=="pci0000:00"
    SUBSYSTEMS==""
    DRIVERS==""
    ATTRS{power/control}=="auto"
    ATTRS{power/runtime_active_time}=="0"
    ATTRS{power/runtime_status}=="unsupported"
    ATTRS{power/runtime_suspended_time}=="0"
    ATTRS{waiting_for_supplier}=="0"

The script invoked is nothing too complicated. It basically just contains a single call to pkill to send a signal to i3blocks.

Why isn’t the script invoked at the moment the bluetooth connection is made? I even added the ACTION="add" to the rule but to no avail.

My intuition tells me that this has something to do with the order of events, which seems to follow the LIFO model based on udevadm monitor’s output (perhaps I shouldn’t use the SUBSYSTEM key?). But as a beginner, I have yet the experience to decipher the output.

What am I missing?