drivers - Lenovo Flex 1480 w/ intel GPU brightness control doesn't work Ubuntu 16.10 - Ask Ubuntu

i have 1 problem not able fix on lenovo flex 1480. problem brightness control. brightness keyboard control aren't working.

i have tried many of solutions on web , nothing has worked far.

i have written conf file looks :

section "device"     identifier  "card0"     driver      "intel"     option      "accelmethod"     "sna"     option      "backlight"       "intel_backlight"     busid       "pci:0:2:0" endsection 

then have changed /etc/default/grub have acpi_backlight=vendor hasn't made change.

i have tried xbacklight, nothing seems work it. getting xrandr error.

well, last hope make work! guys suggestions or help! have hope in community!

p.s

this comes out of lspci -v | grep -i -a 15 vga

00:02.0 vga compatible controller: intel corporation hd graphics 520 (rev 07) (prog-if 00 [vga controller])     subsystem: lenovo hd graphics 520     flags: bus master, fast devsel, latency 0, irq 278     memory @ d0000000 (64-bit, non-prefetchable) [size=16m]     memory @ c0000000 (64-bit, prefetchable) [size=256m]     i/o ports @ e000 [size=64]     [virtual] expansion rom @ 000c0000 [disabled] [size=128k]     capabilities: [40] vendor specific information: len=0c <?>     capabilities: [70] express root complex integrated endpoint, msi 00     capabilities: [ac] msi: enable+ count=1/1 maskable- 64bit-     capabilities: [d0] power management version 2     capabilities: [100] #1b     capabilities: [200] address translation service (ats)     capabilities: [300] #13     kernel driver in use: i915     kernel modules: i915 

i have added grub grub_cmdline_linux="acpi_osi=linux"

after sudo update-grub

and rebooted, xbacklight seems working. have bound keys increase , decrease brightness. still, isn't working fn+f11 , fn+f12, seems undetected computer somehow (i tested out scancode).

this fine workaround now.