ASUS X54C have same problem. Fn + F9 not working.
tomasz@ASUS-X54C:~/tmp$ tree /proc/acpi/ /proc/acpi/ ├── button │ └── lid │ └── LID │ └── state ├── event └── wakeup
Kernel: Linux ASUS-X54C 3.11.0-4-generic #9-Ubuntu SMP Mon Aug 26 15:21:06 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux OS: Ubuntu 13.10 x64
ASUS X54C have same problem. Fn + F9 not working.
tomasz@ ASUS-X54C: ~/tmp$ tree /proc/acpi/
/proc/acpi/
├── button
│ └── lid
│ └── LID
│ └── state
├── event
└── wakeup
Kernel: Linux ASUS-X54C 3.11.0-4-generic #9-Ubuntu SMP Mon Aug 26 15:21:06 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
OS: Ubuntu 13.10 x64