Description of problem:

I'm using a Lenovo T530 running Fedora 20, and the Brightness-Up key only seems to do anything when logged in through Gnome.  Brightness-Down works in all the window managers I tried, but Brightness-Up doesn't even bring up the pop-up.

In xev, Brightness-Up shows up as a KeyPress/KeyRelease, Brightness-Down (which works perfectly) does not:

KeyPress event, serial 37, synthetic NO, window 0x2e00001,
    root 0xa6, subw 0x0, time 7489730, (-461,-86), root:(410,358),
    state 0x0, keycode 233 (keysym 0xffd1, F20), same_screen YES,
    XLookupString gives 0 bytes: 
    XmbLookupString gives 0 bytes: 
    XFilterEvent returns: False

KeyRelease event, serial 37, synthetic NO, window 0x2e00001,
    root 0xa6, subw 0x0, time 7489730, (-461,-86), root:(410,358),
    state 0x0, keycode 233 (keysym 0xffd1, F20), same_screen YES,
    XLookupString gives 0 bytes: 
    XFilterEvent returns: False


xfce4-power-manager --debug shows this for the Brightness-Down key (nothing for Brightness-Up):


TRACE[xfpm-button.c:114] xfpm_button_filter_x_events(): Key press: ((XfpmButtonKey) BUTTON_MON_BRIGHTNESS_DOWN)
TRACE[xfpm-backlight.c:219] xfpm_backlight_show(): Level 6
TRACE[xfpm-manager.c:259] xfpm_manager_button_pressed_cb(): Received button press event: ((XfpmButtonKey) BUTTON_MON_BRIGHTNESS_DOWN)
Version-Release number of selected component (if applicable):
kernel.x86_64                           3.16.2-201.fc20
xfce4-power-manager.x86_64              1.2.0-9.fc20


How reproducible:
100%

Steps to Reproduce:
1. Press Brightness-Down (Fn-F8)
2. Press Brightness-Up (Fn-F9)

Actual results:
Screen gets dimmer (brightness pop-up visible), doesn't get brighter (brightness pop-up NOT visible).

Expected results:
Screen gets dimmer (brightness pop-up visible), then gets brighter (brightness pop-up visible).

Additional info:

My only workarounds so far are (a) stop everything, log out of XFCE and into Gnome to increase the brightness, or (b):

    sudo sh -c 'echo 1500 > /sys/class/backlight/intel_backlight/brightness'