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

Question

I have one problem that I was not able to fix on my Lenovo Flex 1480. The problem is my brightness control. My brightness keyboard control aren't working.

I have tried many of the solutions on the Web and nothing has worked so far.

I have written a conf file which looks like this :

Section "Device"
    Identifier  "card0"
    Driver      "intel"
    Option      "AccelMethod"     "sna"
    Option      "Backlight"       "intel_backlight"
    BusID       "PCI:0:2:0"
EndSection

Then I have changed /etc/default/grub to have acpi_backlight=vendor which hasn't made a change.

I have tried xbacklight, but nothing seems to work with it. I am getting a Xrandr error.

Well, this is my last hope to make this work! Thanks guys for any suggestions or help! I have hope in this community!

P.S

this is what 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 at d0000000 (64-bit, non-prefetchable) [size=16M]
    Memory at c0000000 (64-bit, prefetchable) [size=256M]
    I/O ports at e000 [size=64]
    [virtual] Expansion ROM at 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

Answer 1

I have added to grub GRUB_CMDLINE_LINUX="acpi_osi=Linux"

After sudo update-grub

and rebooted, xbacklight seems to be working. So I have bound keys to increase and decrease brightness. But still, it isn't working with fn+f11 and fn+f12, it seems to be undetected by the computer somehow (I tested it out with scancode).

This is a fine workaround for now.