# brightness control



## TCE (Feb 23, 2010)

Has anybody found a way to adjust brightness on a HP laptop G50 or similar?  Tried alot of how tos with any success.


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## TCE (Feb 23, 2010)

I have heard of ways to controls this through sysctl commands, but when I tried some of them but did not work.


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## lme@ (Feb 23, 2010)

Have you tried to kldload 'acpi_hp'?


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## TCE (Feb 23, 2010)

yes i tried that with no luck and acpi_video.


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## TCE (Feb 23, 2010)

Ime@ does loading the acpi_hp work for you?


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## lme@ (Feb 24, 2010)

Yes:

```
<FreeBSD 8.0-RELEASE-p2> [pcbsd:~] # kldload acpi_hp
```


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## richardpl (Feb 24, 2010)

There is no point in loading acpi_hp if nothing is showed in console after that.
Show output of related sysctls for acpi_video. Also show output, if any, after loading acpi_hp.


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## TCE (Feb 25, 2010)

Ime@ can you please give me info on how you were able to get your brightness control working on your computer would be helpful


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## lme@ (Feb 25, 2010)

TCE: On my Thinkpad it "just works" out of the box.
I don't have a HP notebook.


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## sahne (Feb 26, 2010)

hi,

have you tried the updated acpi_video module ?
there were changes regarding the brightness commands about 2 weeks ago.
currently the driver is only modified on CURRENT, but I've posted a patch for STABLE on freebsd-acpi@ 

http://lists.freebsd.org/pipermail/freebsd-acpi/2010-February/006326.html


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## harishankar (May 10, 2010)

Try this with kldload() and acpi_video().


```
#kldload acpi_video

#sysctl hw.acpi.video
```
(This will list the variables and their settings this will let you see what "levels" of brightness are supported)


```
#sysctl hw.acpi.video.<device>.brightness=<level>
```
(where <device> is a device, can be crt0 crt1 lcd0 etc.) and level is an acceptable level)

This works for me, but I still don't know how to key map this functionality to the FN+F7 and FN+F8 keys.


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