(Solved) brightness controls not working on mint 22.3/Cinnamon | Linux Mint Community🍵 | Page 1

fossil dagger Mar 25, 2026, 12:31 PM

#

Hey so mint is unable to detect my brightness control keys on my hp laptop
I tried rebinding on the keyboard settings but it just doesn't detect em
The Fn Keys work and I'm sure about that
I tried em on both X11 and Wayland

#

for more context, the brightness slider in the battery/power applet works but the brightness controls in my laptop F2 and F3 keys (lower/increase brightness respectively) doesnt work

fluid citrus Mar 25, 2026, 12:54 PM

#

I'm guessing other Fn combinations work, like volume?

fossil dagger Mar 25, 2026, 12:54 PM

#

yep those do

#

i have also tested if the f2 and f3 keys are broken but they are not

fluid citrus Mar 25, 2026, 12:55 PM

#

And the brightness slider actually changes the brightness properly?

fossil dagger Mar 25, 2026, 12:55 PM

#

yep

fluid citrus Mar 25, 2026, 12:56 PM

#

Let's see the system info. In the terminal type

inxi -SMGxxx

show the results

fossil dagger Mar 25, 2026, 12:57 PM

#

here it is

📎 inxi_log.txt

fluid citrus Mar 25, 2026, 1:00 PM

#

And you're sure F2 and F3 keys work by themselves?

fossil dagger Mar 25, 2026, 1:00 PM

#

yep

fluid citrus Mar 25, 2026, 1:06 PM

#

In the terminal run

xev | grep keycode

then press Fn+F2 and Fn+F3 once, then close the white wondow that appeared after the command and show the output.

fossil dagger Mar 25, 2026, 1:07 PM

#

fluid citrus In the terminal run xev | grep keycode then press Fn+F2 and Fn+F3 once, then...

nesper8@mint:~$ xev | grep keycode
    state 0x10, keycode 36 (keysym 0xff0d, Return), same_screen YES,

#

when not using the fnkey

nesper8@mint:~$ xev | grep keycode
    state 0x10, keycode 36 (keysym 0xff0d, Return), same_screen YES,
    state 0x10, keycode 68 (keysym 0xffbf, F2), same_screen YES,
    state 0x10, keycode 68 (keysym 0xffbf, F2), same_screen YES,
    state 0x10, keycode 69 (keysym 0xffc0, F3), same_screen YES,
    state 0x10, keycode 69 (keysym 0xffc0, F3), same_screen YES,

fluid citrus Mar 25, 2026, 1:08 PM

#

And when using combination for volume?

fossil dagger Mar 25, 2026, 1:10 PM

#

nesper8@mint:~$ xev | grep keycode
    state 0x10, keycode 36 (keysym 0xff0d, Return), same_screen YES,

pressed mute, volume down, vulume up twice respectively

#

but those do change volume

fluid citrus Mar 25, 2026, 1:10 PM

#

And the output from these keys?

fossil dagger Mar 25, 2026, 1:12 PM

#

xev output without grep for the volume keys

ocusOut event, serial 37, synthetic NO, window 0x5800001,
    mode NotifyGrab, detail NotifyAncestor

FocusIn event, serial 37, synthetic NO, window 0x5800001,
    mode NotifyUngrab, detail NotifyAncestor

KeymapNotify event, serial 37, synthetic NO, window 0x0,
    keys:  2   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   
           0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   

FocusOut event, serial 37, synthetic NO, window 0x5800001,
    mode NotifyGrab, detail NotifyAncestor

FocusIn event, serial 37, synthetic NO, window 0x5800001,
    mode NotifyUngrab, detail NotifyAncestor

KeymapNotify event, serial 37, synthetic NO, window 0x0,
    keys:  100 0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   
           0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   

FocusOut event, serial 37, synthetic NO, window 0x5800001,
    mode NotifyGrab, detail NotifyAncestor

FocusIn event, serial 37, synthetic NO, window 0x5800001,
    mode NotifyUngrab, detail NotifyAncestor

KeymapNotify event, serial 37, synthetic NO, window 0x0,
    keys:  2   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   
           0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   

ClientMessage event, serial 37, synthetic YES, window 0x5800001,
    message_type 0x156 (WM_PROTOCOLS), format 32, message 0x154 (WM_DELETE_WINDOW)

#

the brightness keys dont register at all in xev

#

while F2 and F3 does without holding the Fn Key

fluid citrus Mar 25, 2026, 1:13 PM

#

What's the key combo for volume? Fn+F5 / F6 ?

fossil dagger Mar 25, 2026, 1:14 PM

#

Fn+F6 for mute
Fn+F7 for VolDown
Fn+F8 for VolUp

#

Model Name: HP 15s-gr0011AU

fluid citrus Mar 25, 2026, 1:21 PM

#

Let's try

sudo evtest

from the list, select your keyboard, then press Fn+f2 / f3, see if there is any (new) output when you press them. Press ctrl+c to exit the command.

fossil dagger Mar 25, 2026, 1:22 PM

#

1 sec
have to install it first

#

Event: time 1774445043.798316, type 4 (EV_MSC), code 4 (MSC_SCAN), value ab
Event: time 1774445043.798316, -------------- SYN_REPORT ------------
Event: time 1774445043.807799, type 4 (EV_MSC), code 4 (MSC_SCAN), value ab
Event: time 1774445043.807799, -------------- SYN_REPORT ------------
Event: time 1774445044.416839, type 4 (EV_MSC), code 4 (MSC_SCAN), value ab
Event: time 1774445044.416839, -------------- SYN_REPORT ------------
Event: time 1774445044.426060, type 4 (EV_MSC), code 4 (MSC_SCAN), value ab
Event: time 1774445044.426060, -------------- SYN_REPORT ------------

fluid citrus Mar 25, 2026, 1:26 PM

#

this is for fn+f2 / f3 ?

fossil dagger Mar 25, 2026, 1:26 PM

#

yep

fluid citrus Mar 25, 2026, 1:26 PM

#

ok.. does

lsmod | grep hp_wmi

show anything?

fossil dagger Mar 25, 2026, 1:27 PM

#

nesper8@mint:~$ lsmod | grep hp_wmi
hp_wmi                 36864  0
sparse_keymap          12288  1 hp_wmi
platform_profile       20480  1 hp_wmi
wmi                    28672  3 hp_wmi,video,wmi_bmof

fluid citrus Mar 25, 2026, 1:31 PM

#

fossil dagger ``` Event: time 1774445043.798316, type 4 (EV_MSC), code 4 (MSC_SCAN), value ab ...

Does it say "value ab" for both fn+f2 and fn+f3? What about fn+f5?

fossil dagger Mar 25, 2026, 1:32 PM

#

Properties:
Testing ... (interrupt to exit)
Event: time 1774445500.399965, type 4 (EV_MSC), code 4 (MSC_SCAN), value 1c
Event: time 1774445500.399965, type 1 (EV_KEY), code 28 (KEY_ENTER), value 0
Event: time 1774445500.399965, -------------- SYN_REPORT ------------
Event: time 1774445504.347731, type 4 (EV_MSC), code 4 (MSC_SCAN), value ab
Event: time 1774445504.347731, -------------- SYN_REPORT ------------
Event: time 1774445504.357254, type 4 (EV_MSC), code 4 (MSC_SCAN), value ab
Event: time 1774445504.357254, -------------- SYN_REPORT ------------
Event: time 1774445505.088409, type 4 (EV_MSC), code 4 (MSC_SCAN), value ab
Event: time 1774445505.088409, -------------- SYN_REPORT ------------
Event: time 1774445505.099060, type 4 (EV_MSC), code 4 (MSC_SCAN), value ab
Event: time 1774445505.099060, -------------- SYN_REPORT ------------
Event: time 1774445510.760652, type 4 (EV_MSC), code 4 (MSC_SCAN), value a0
Event: time 1774445510.760652, type 1 (EV_KEY), code 113 (KEY_MUTE), value 1
Event: time 1774445510.760652, -------------- SYN_REPORT ------------
Event: time 1774445510.770528, type 4 (EV_MSC), code 4 (MSC_SCAN), value a0
Event: time 1774445510.770528, type 1 (EV_KEY), code 113 (KEY_MUTE), value 0
Event: time 1774445510.770528, -------------- SYN_REPORT ------------

#

first 2 for Fn+F2, then for Fn+F3 and final 2 for Fn+F6

#

Fn+F5 is blank

fluid citrus Mar 25, 2026, 1:38 PM

#

What's on fn+f5?

fossil dagger Mar 25, 2026, 1:39 PM

#

its blank

#

fluid citrus Mar 25, 2026, 1:40 PM

#

Oh, i thought it was volume related, my bad

#

So the problem is that Fn+f2 and fn+f3 send the same code, so the system is confused what to do with it. Looking for workarounds

#

Ok, let's test a few things.

sudo brightnessctl set 20%-
sudo brightnessctl set +20%

should change brightness, yes?

fossil dagger Mar 25, 2026, 1:52 PM

#

Yep I tried it before opening the issue
Both works

fluid citrus Mar 25, 2026, 1:54 PM

#

I'm planning to bind different key combos to brightness as a workaround, is this acceptable?

fossil dagger Mar 25, 2026, 1:55 PM

#

It's a little bit pita cuz I've been using this button combo since 2016 on my first laptop which was also an hp

fluid citrus Mar 25, 2026, 2:00 PM

#

Alright..... do you know how to set kernel parameters?

fossil dagger Mar 25, 2026, 2:00 PM

#

Yes

fluid citrus Mar 25, 2026, 2:02 PM

#

Ok, let's try a few (one at a time) see if they change anything.

acpi_backlight=vendor
acpi_backlight=native
acpi_backlight=video

fossil dagger Mar 25, 2026, 2:05 PM

#

acpi_backlight=native worked

#

Thank you very much

fluid citrus Mar 25, 2026, 2:06 PM

#

Ok, both keys work?

fossil dagger Mar 25, 2026, 2:06 PM

#

Yes

fluid citrus Mar 25, 2026, 2:06 PM

#

Cool. Have a nice day then.

fossil dagger Mar 25, 2026, 2:07 PM

#

Thank you so much again mate

#

(Solved) brightness controls not working on mint 22.3/Cinnamon

fossil dagger Mar 25, 2026, 3:53 PM

#

@fluid citrus sorry for pinging but it stopped working after a reboot

#

brightness controls not working on mint 22.3/Cinnamon

fluid citrus Mar 25, 2026, 3:55 PM

#

What does

cat /proc/cmdline

say right now?

fossil dagger Mar 25, 2026, 3:57 PM

#

nesper8@mint:~$ cat /proc/cmdline 
BOOT_IMAGE=/vmlinuz-6.17.0-19-generic root=/dev/mapper/vgmint-root ro quiet splash acpi_backlight=native

#

im tired
ill rebind the keys

#

thank you so much again

#

(Solved) brightness controls not working on mint 22.3/Cinnamon

#(Solved) brightness controls not working on mint 22.3/Cinnamon