Created attachment 104908 [details]
dmesg | grep Microsoft

HID device 'USB HID v1.11 Mouse' provided by Microsoft Wireless Optical
Desktop® 2.20 (connected to USB and identified as vendor 0x45e, product
0xe3, version 0x111) is reported as supporting EV_ABS event with ABS_MT_SLOT
code, but nevertheless libevdev_get_num_slots returns -1.

It means that mouse isn't recognized by libinput as a valid device, it's discarded and doesn't work in Weston.

As partially explained by LKML message [1] (Message-Id [2]):

    The root of the problem comes from hid-input, which maps unknown axis
    to ABS_MISC. However, when an event code is already in use, hid-input
    uses the one after, leading to uses of ABS_MISC + N, where N is the
    number of unknown axis.

    We are encountering a problem with the multitouch protocol here because
    if a device has more than 7 unknown axis (which is the case for the PS3
    Sixaxis controller), then the unknown axis get maps to ABS_MT_SLOT and
    beyond.

Initial discussion of libinput patch fixing problem for mouse from Wireless Optical Desktop is at [3].

In my tests with evtest mouse didn't produce any MT_* events.

[1] https://lkml.org/lkml/2013/11/20/515
[2] 1384983141-31019-1-git-send-email-benjamin.tissoires@redhat.com
[3] http://lists.freedesktop.org/archives/wayland-devel/2014-August/016603.html