# [SOLVED]Brightness CNTRL Via Function Key

## slicktux

i solved the problem by adding Kernel Parameter 'acpi_backlight=vendor'

Hi all!

I just recently upgraded my kernel from 3.8.13 to 3.10.7, and my Fn+Brightness +or- no longer work when booting from the new kernel only. 

I need help troubleshooting, thank you!

Edit: may i add that the Fn+Volume do work i am only having problems with the Brightness

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## Hu

Please provide much more information.  We can guess from your reference to Fn that this is probably a laptop keyboard.  What vendor, make, and model is this laptop?  What year was it built?  What procedure did you use to configure the new kernel?  In the old kernel, was brightness handled purely by the kernel or did it generate some event that a user process handled to perform the change?

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## slicktux

My Apologies,

Laptop Specs

Lenovo v570

Problem: Brightness Control

Via:Function Key

Via:PowerManagement

Kernel Configuration from 3.8.13 to Kernel 3.10.7

I used the .config from 3.8.13 for Kernel 3.10.7 and ran "make menuconfig"  for Kernel 3.10.7, finished revising kernel changes and compiled Kernel 3.10.7. I do not recall having to specifically configure my old kernel in-order  to have the (Function+ "+" or "-")<<"brightness control on keyboard" to work.

On the old Kernel when my laptop's battery starts loosing juice the brightness would automatically get lowered,  with the new Kernel it attempts to do the same (i know because the brightness bar appears) but the brightness is not affected. So i have two problems i can not control my Screen Brightness Manually via Function Key or automatically Via Power Management.

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## wpkzz

Hi mates:

I have a very similar problem. I think it has to do with acpi configuration and options in the kernel, regarding the hotkeys and laptop-extras. 

In the kernel 3.8.13 I more or less managed to get most of my hotkeys to work, but some of the most fundamentals were simply too elusive.

Detailing: I have an asus N76V machine, very good and powerfull thing. It has the following hotkeys (Fn keys).

In the second column I put an "x" if it has never worked, an "h" it it worked with 3.8, and a "y" it it works with 3.10.7  

```

Sleep mode                                 x

Antena off/on                               x

keyboard brightness down             y 

keyboard brightness up                 y

screen brightness down                 x

screen brightness up                     x

screen off                                     y

screen to projector                        ?

touchpad out                                 h

mute                                             y

sound down                                   y

sound up                                       y

A very funny thing marked "S" on the C (skype?)  y

Camera           y

A man running on the spacebar    h

Audio Play, pause, next, prev, stop.  y

A Calculator on the numkey entr.  y 

```

Now I have the following kernel modules relevant to this post loaded:

```

 # lsmod

...mxm_wmi                 1347  0 

asus_wmi               15697  1 asus_nb_wmi

pci_hotplug            10432  1 asus_wmi

...

```

In the kernel I have the folowing options:

```
                

Power management and ACPI options  --->                                        

            [*] Suspend to RAM and standby                                                     

             [*] Hibernation (aka 'suspend to disk')                                            

          [*] ACPI (Advanced Configuration and Power Interface) Support  ---> 

                    --- ACPI (Advanced Configuration and Power Interface) Support                      x x  

  x x            [*]   Deprecated /proc/acpi files                                                  x x  

  x x            [ ]   Deprecated power /proc/acpi directories                                      x x  

  x x            < >   EC read/write access through /sys/kernel/debug/ec                            x x  

  x x            [*]   Deprecated /proc/acpi/event support                                          x x  

  x x            <*>   AC Adapter                                                                   x x  

  x x            <*>   Battery                                                                      x x  

  x x            -*-   Button                                                                       x x  

  x x            -*-   Video                                                                        x x  

  x x            <*>   Fan                                                                          x x  

  x x            [*]   Dock                                                                         x x  

  x x            <*>   Processor                                                                    x x  

  x x            < >   Processor Aggregator                                                         x x  

  x x            <*>   Thermal Zone                                                                 x x  

  x x            -*-   NUMA support                                                                 x x  

  x x            [ ]   ACPI tables override via initrd                                              x x  

  x x            [ ]   Debug Statements                                                             x x  

  x x            [ ]   PCI slot detection driver                                                    x x  

  x x            -*-   Container and Module Devices                                                 x x  

  x x            < >   Smart Battery System                                                         x x  

  x x            < >   Hardware Error Device                                                        x x  

  x x            <M>   Allow ACPI methods to be inserted/replaced at run time                       x x  

  x x            [ ]   Boottime Graphics Resource Table support                                     x x  

  x x            [ ]   ACPI Platform Error Interface (APEI)        

----> Device Drivers

           [*] X86 Platform Specific Device Drivers  --->                                     

             <*>   Asus Laptop Extras                     

  <M>   ASUS WMI Driver                                                              x x  

  x x            <M>     Asus Notebook WMI Driver                                                   x x  

  x x            <M>     Eee PC WMI Driver                                                          x x  

  x x            <*>   WMI                                                                          x x  

  x x            <M>     MSI WMI extras    

                 (everything else in this section turned off).

```

Well, that seems to be it. Another question  is how do you people manage to make this beautifull diagrams for their menuconfig? The ones that look exactly like that but

without the innecesary bits?

Read you soon!

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