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USB device plugged in again after removing it while being in use:

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

KERNEL[36.067804] remove   /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.5/dvb/dvb0.net0 (dvb)
...
UDEV  [36.081497] remove   /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.5/dvb/dvb0.dvr0 (dvb)

When plugging it in again, no add event is logged - no matter what device I plug in (keyboard, mouse, Bluetooth dongle, ...).

USB device not in use, pluggin it in and pulling it out:

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

KERNEL[54.325134] add      /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.4 (usb)
...
UDEV  [55.388867] add      /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.4/rc/rc0/input0/event0 (input)
KERNEL[59.878645] remove   /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.4/dvb/dvb0.net0 (dvb)
...
UDEV  [59.965779] remove   /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.4 (usb)
KERNEL[64.311664] add      /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.4 (usb)
...

When I do not start the process or stop it before unplugging or replugging I see more events, especially the add events.

I do get all events when stopping the process that uses the "blocking" device. I even don't get kernel: log messages in kern.log and messages either.

Kernel 4.4, Debian 9.0 (Raspbian 8.0 upgraded to Stretch 9.0)

Linux raspberrypi 4.4.38-v7+ #938 SMP Thu Dec 15 15:22:21 GMT 2016 armv7l GNU/Linux

I understand that the kernel might be unable to properly unregister and re-register the devices when it's in use, but why do I not get add events for any device at all?

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