I have a VAIO laptop (VPCS116FG, S series). Its keyboard has sensors that can detect how bright the surrounding is, so it automatically turns on the backlight in dark places such as airplane cabins. Since I've moved to Ubuntu from Windows 7, the backlight sensor doesn't work at all.
By googling the issue, I found this website and followed the instructions, but at the compilation step, I was met with the following errors:
sa/file_funcs.c: In function ‘get_first_backlight_device_name’: sa/file_funcs.c:44:9: warning: format ‘%li’ expects argument of type ‘long int’, but argument 2 has type ‘unsigned int’ [-Wformat] /tmp/ccIhKx5v.o: In function `handle_acpi_events': acpi_funcs.c:(.text+0xf8): undefined reference to `log' acpi_funcs.c:(.text+0x109): undefined reference to `log' acpi_funcs.c:(.text+0x120): undefined reference to `pow' collect2: ld returned 1 exit status
How do I make it work?