Fn keys recognised but not handled after 17.04 upgrade

[Donjan Rodic]

Ubuntu 17.04 amd64 upgraded from 16.10 on a Thinkpad T460p, gnome-flashback Compiz session.

The Fn keys (media keys, brightness, XF86Search, etc.) have stopped working: all except XF86WLAN, which manages to toggle the wireless state, do nothing.
They are visible in xev:

KeyPress event, serial 62, synthetic NO, window 0x4e00001,
    root 0xf8, subw 0x4e00002, time 34775899, (50,45), root:(51,102),
    state 0x2010, keycode 123 (keysym 0x1008ff13, XF86AudioRaiseVolume), same_screen YES,
    XLookupString gives 0 bytes:
    XmbLookupString gives 0 bytes:
    XFilterEvent returns: False

and others like XF86AudioMute, XF86MonBrightnessUp, etc. neither affect the hardware nor show a notification.

I can change the brightness through
/sys/class/backlight/intel_backlight/brightness
or with the System Settings -> Power -> Screen Brightness slider, and changing audio with the applet works too, so the drivers/modules appear to function well, but the events are not handled presumably by g-s-d (?).

In System Settings -> Keyboard the shortcut for e.g. Volume Down is set to "Audio lower volume", and resetting to default as well as setting it via the keyboard doesn't change the situation.

dmesg and journalctl -f are coming up empty (except for the correctly working XF86WLAN).

I'd rather have this work properly instead of keybinding to amixer (with manually sent osd) or brightness file writing...

Any suggestions?

ProblemType: Bug
DistroRelease: Ubuntu 17.04
Package: gnome-settings-daemon 3.24.2-0ubuntu0.1
ProcVersionSignature: Ubuntu 4.10.0-21.23-generic 4.10.11
Uname: Linux 4.10.0-21-generic x86_64
ApportVersion: 2.20.4-0ubuntu4.1
Architecture: amd64
CurrentDesktop: GNOME-Flashback:GNOME
Date: Sun Jun 4 15:09:04 2017
InstallationDate: Installed on 2016-10-25 (221 days ago)
InstallationMedia: Ubuntu 16.10 "Yakkety Yak" - Release amd64 (20161012.2)
SourcePackage: gnome-settings-daemon
UpgradeStatus: Upgraded to zesty on 2017-05-31 (3 days ago)
mtime.conffile..etc.xdg.autostart.gnome-settings-daemon.desktop: 2017-05-31T23:37:45.416621
mtime.conffile..etc.xdg.autostart.org.gnome.SettingsDaemon.A11yKeyboard.desktop: 2017-05-31T23:37:45.416621
mtime.conffile..etc.xdg.autostart.org.gnome.SettingsDaemon.A11ySettings.desktop: 2017-05-31T23:37:45.416621
mtime.conffile..etc.xdg.autostart.org.gnome.SettingsDaemon.Clipboard.desktop: 2017-05-31T23:37:45.416621
mtime.conffile..etc.xdg.autostart.org.gnome.SettingsDaemon.Color.desktop: 2017-05-31T23:37:45.416621
mtime.conffile..etc.xdg.autostart.org.gnome.SettingsDaemon.Datetime.desktop: 2017-05-31T23:37:45.416621
mtime.conffile..etc.xdg.autostart.org.gnome.SettingsDaemon.Housekeeping.desktop: 2017-05-31T23:37:45.416621
mtime.conffile..etc.xdg.autostart.org.gnome.SettingsDaemon.Keyboard.desktop: 2017-05-31T23:37:45.416621
mtime.conffile..etc.xdg.autostart.org.gnome.SettingsDaemon.MediaKeys.desktop: 2017-05-31T23:37:45.416621
mtime.conffile..etc.xdg.autostart.org.gnome.SettingsDaemon.Mouse.desktop: 2017-05-31T23:37:45.416621
mtime.conffile..etc.xdg.autostart.org.gnome.SettingsDaemon.Orientation.desktop: 2017-05-31T23:37:45.416621
mtime.conffile..etc.xdg.autostart.org.gnome.SettingsDaemon.Power.desktop: 2017-05-31T23:37:45.416621
mtime.conffile..etc.xdg.autostart.org.gnome.SettingsDaemon.PrintNotifications.desktop: 2017-05-31T23:37:45.416621
mtime.conffile..etc.xdg.autostart.org.gnome.SettingsDaemon.Rfkill.desktop: 2017-05-31T23:37:45.416621
mtime.conffile..etc.xdg.autostart.org.gnome.SettingsDaemon.ScreensaverProxy.desktop: 2017-05-31T23:37:45.416621
mtime.conffile..etc.xdg.autostart.org.gnome.SettingsDaemon.Sharing.desktop: 2017-05-31T23:37:45.416621
mtime.conffile..etc.xdg.autostart.org.gnome.SettingsDaemon.Smartcard.desktop: 2017-05-31T23:37:45.416621
mtime.conffile..etc.xdg.autostart.org.gnome.SettingsDaemon.Sound.desktop: 2017-05-31T23:37:45.416621
mtime.conffile..etc.xdg.autostart.org.gnome.SettingsDaemon.Wacom.desktop: 2017-05-31T23:37:45.416621
mtime.conffile..etc.xdg.autostart.org.gnome.SettingsDaemon.XRANDR.desktop: 2017-05-31T23:37:45.416621
mtime.conffile..etc.xdg.autostart.org.gnome.SettingsDaemon.XSettings.desktop: 2017-05-31T23:37:45.416621

[Donjan Rodic (bryonak)]

Update: the Unity session as well as the sessions from the packages ubuntu-mate-desktop and cinnamon-desktop correctly handle all Fn keys.
I'm stuck with Cinnamon for now.