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