Dell laptop function keys stopped working between 5.10.46 and 5.13.9

[Paul Menzel]

Dear Linux folks,


On a Dell Latitude E7250, updating Linux from 5.10.46 to 5.13.9 (Debian 
sid/unstable) the two function keys to (un-)mute the microphone, and 
enable/disable Wifi stopped working. The other function keys continue to 
work. The `evtest` output did not change.

    Linux version 5.10.0-8-amd64 (debian-kernel@xxxxxxxxxxxxxxxx) 
(gcc-10 (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for 
Debian) 2.35.2) #1 SMP Debian 5.10.46-4 (2021-08-03)

    Event: time 1629104514.184947, type 4 (EV_MSC), code 4 (MSC_SCAN), 
value 88
    Event: time 1629104514.184947, type 1 (EV_KEY), code 240 
(KEY_UNKNOWN), value 2

    Linux version 5.13.0-trunk-amd64 (debian-kernel@xxxxxxxxxxxxxxxx) 
(gcc-10 (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for 
Debian) 2.35.2) #1 SMP Debian 5.13.9-1~exp2 (2021-08-10)

    Event: time 1629103829.341409, type 4 (EV_MSC), code 4 (MSC_SCAN), 
value 88
    Event: time 1629103829.341409, type 1 (EV_KEY), code 240 
(KEY_UNKNOWN), value 2

The output of `acpi_listen` also did not change.

    $ acpi_listen
     9DBB5994-A997- 000000d0 00000000

Are you aware of such reports?


Kind regards,

Paul