Ok, brightness changing works fine even without blacklisted sonpyi if this bug https://bugs.launchpad.net/ubuntu/+source/acpi-support/+bug/136380 has been fixed. So no kernel change is needed.
Ok, brightness changing works fine even without blacklisted sonpyi if this bug https:/ /bugs.launchpad .net/ubuntu/ +source/ acpi-support/ +bug/136380 has been fixed.
So no kernel change is needed.