Comment 84 for bug 1581088

Discovered this problem yesterday, which led me to this bug-report:

Middle-button clicking was dead and didn't work on a clean new xenial install,
same mouse works fine on an upgraded PC.

Testing with xev showed nothing on the new PC: Middle button clicks were not recognised.

"xinput list" told the mouse was:
 "PixArt HP USB Optical Mouse id=1 [slave pointer (2)]

Ran a few "xinput test <ID>" commands. (NOT only on the mouse's ID (15) but a another to initially, lower number, typo.)

And alas: Middle button clicks were suddenly detected and worked like charm - for half an hour.
Then it died again.

I repeated the "xinput test" deal, now on several ID's, lastly the mouse.
After this, the middle button clicks were once again detected.

This time i rebooted the PC, power-pff/on. Wheel-clicking survived the reboot and still works,
36 hours later or so.

I'm not a kernel person but as an old-time user I got a little back-flash to the days of kernel 2.0,
 when devices often had to be added and linked manually.

A look in /dev revealed several recent changes, from the time of the xinput tests.

Grep'ed around and found:

me@pc:/dev$ ls -latr |grep "11:48"
drwxr-xr-x 4 root root 520 Dec 16 11:48 input
drwxr-xr-x 21 root root 4200 Dec 16 11:48 .
crw------- 1 root root 247, 0 Dec 16 11:48 hidraw0
drwxr-xr-x 2 root root 4140 Dec 16 11:48 char

me@pc:/dev/input$ ls -latr |grep "11:48"
drwxr-xr-x 21 root root 4200 Dec 16 11:48 ..
drwxr-xr-x 4 root root 520 Dec 16 11:48 .
crw-rw---- 1 root input 13, 34 Dec 16 11:48 mouse2
crw-rw---- 1 root input 13, 80 Dec 16 11:48 event16
drwxr-xr-x 2 root root 220 Dec 16 11:48 by-path
drwxr-xr-x 2 root root 100 Dec 16 11:48 by-id

me@pc:/dev/input/by-path$ ls -latr |grep "11:48"
drwxr-xr-x 4 root root 520 Dec 16 11:48 ..
lrwxrwxrwx 1 root root 9 Dec 16 11:48 pci-0000:00:14.0-usb-0:1:1.0-mouse -> ../mouse2
lrwxrwxrwx 1 root root 10 Dec 16 11:48 pci-0000:00:14.0-usb-0:1:1.0-event-mouse -> ../event16

me@pc:/dev/input/by-id$
drwxr-xr-x 4 root root 520 Dec 16 11:48 ..
lrwxrwxrwx 1 root root 9 Dec 16 11:48 usb-PixArt_HP_USB_Optical_Mouse-mouse -> ../mouse2
lrwxrwxrwx 1 root root 10 Dec 16 11:48 usb-PixArt_HP_USB_Optical_Mouse-event-mouse -> ../event16
drwxr-xr-x 2 root root 100 Dec 16 11:48 .

me@pc:/dev/char$
lrwxrwxrwx 1 root root 18 Dec 16 11:48 189:8 -> ../bus/usb/001/009
lrwxrwxrwx 1 root root 10 Dec 16 11:48 247:0 -> ../hidraw0
lrwxrwxrwx 1 root root 15 Dec 16 11:48 13:34 -> ../input/mouse2
lrwxrwxrwx 1 root root 16 Dec 16 11:48 13:80 -> ../input/event16

Hoping the listings above can be of help in solving this annoyance.
I agree "Importance" should be raised to major.