Backlight Function Keys Do Not Work with Latitude E7240 and Linux

Question

Using a linux-4.8.17 kernel with a Latitude E7240, I cannot get the backlight function keys to work. The relevant dell kernel modules seem to be loaded, but nothing happens when I try to use the keys. Any suggestions would be much appreciated ---------- Note that I can change the screen backlight brightness with: # echo 500 > /sys/class/backlight/intel_backlight/brightness ..but not with: # echo 500 > /sys/class/backlight/dell_backlight/brightness $ lsmod | grep delldell_laptop            16384  0 dell_wmi               12288  0 dell_smbios            12288  2 dell_laptop,dell_wmidcdbas                 12288  1 dell_smbiossparse_keymap          12288  1 dell_wmivideo                  28672  2 dell_laptop,dell_wmibacklight              12288  2 dell_laptop,videowmi                    12288  1 dell_wmidell_rbtn              12288  1

Dell-Vijay A · Answer

Hi JUANITO_TC,

You can refer this link http://dell.to/2sFGMVZ.

Let me know if this helps.

Also, please click my DELL-username and write me a private message with the service tag and your Name for case records.

juanito_tc · Answer

Thanks for the reply, but it is the display backlight that does not work via the keyboard function keys. The keyboard backlight does work.

Dell-Vijay A · Answer

Hi, Are you referring to display brightness which you are unable to increase/decrease via keyboard function keys? Was it working before? Also confirm what key combinations are you using?

juanito_tc · Answer

Yes, I am referring to the display brightness, which I am unable to increase/decrease via the keyboard function keys under linux - it works fine under windows

Linux General

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