Originally Posted by dive
Fn keys are usually controlled through acpi events if the hardware doesn't do it alone.
Check out /etc/acpi/acpi_handler.sh
It looks as if Fn+<whatever> does not create ACPI events.
In the default installation, the /etc/acpi/events directory has a single file, defaults, which looks as if it simply passes all events to acpi_handler.sh:
root@CW9:~# cat /etc/acpi/events/default | grep -E -v '^#|^$'
The as-installed acpi_handler.sh reports everything except the power button as "not defined":
root@CW9:~# cat /etc/acpi/acpi_handler.sh | grep -E -v '^#|^$'
case "$1" in
case "$2" in
power) /sbin/init 0
*) logger "ACPI action $2 is not defined"
logger "ACPI group $1 / action $2 is not defined"
Searching the /var/log/* files for such reports shows very few and none associated with Fn+ keys:
root@CW9:/var/log# grep 'ACPI group' * | sed 's/.*logger: //' | sort | uniq
ACPI group ac_adapter / action ADP1 is not defined
ACPI group battery / action BAT1 is not defined
ACPI group processor / action CPU0 is not defined
ACPI group processor / action CPU1 is not defined