Cannot put to sleep HP Compaq notebook

[Giovanni Gigante]

Hello everyone,
I am new at Dragonfly BSD. I'm trying to install on an old notebook, an 
HP Compaq nc8430.
So far most things seem to work (I have also added this information to 
the DF wiki). But I have a problem with power management.

"sysctl hw.acpi" says, among other things:

hw.acpi.supported_sleep_state: S3 S4 S5
hw.acpi.power_button_state: S5
hw.acpi.sleep_button_state: S3
hw.acpi.lid_switch_state: NONE
hw.acpi.standby_state: S1
hw.acpi.suspend_state: S3
hw.acpi.sleep_delay: 1
hw.acpi.s4bios: 1
hw.acpi.verbose: 0

Soft-off works, both from "halt -p" and from hitting the power button. 
However, I am not able to put the computer to 
sleep(/suspend/hibernate/whatever).
"acpiconf -s 1" returns: "acpiconf: request sleep type (1) failed: 
Operation not permitted"
Same result for types 2, 3 and 4.

FWIW, I also tried FreeBSD 10.3. Types 1, 2 and 3 say the same thing. 
Instead "acpiconf -s 4" does something, i.e. put the machine to sleep, 
but then it seems unable to resume.
On Debian Linux 8.6 "systemctl suspend" works correctly both with 
suspend and resume.

What can I do next?

Thanks