# How to increase brightness in bigger steps



## enriquefynn (Aug 6, 2014)

I'm running FreeBSD 10-STABLE on a Lenovo notebook, using Intel HD4000. Everything works perfectly, but the increase/decrease brightness button does it 1 by 1, so I have to press 99 times down, to get from 100% brightness to 1%.

Also xev doesn't recognize the key, I guess ACPI consumes it before it can be reached by X.

Here is `sysctl hw.acpi.video`

```
hw.acpi.video.lcd0.active: 0
hw.acpi.video.lcd0.brightness: 75
hw.acpi.video.lcd0.fullpower: 76
hw.acpi.video.lcd0.economy: 6
hw.acpi.video.lcd0.levels: 76 6 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100
```

And using `acpidump -dt`:

```
(...)
Method (_BCL, 0, NotSerialized)  // _BCL: Brightness Control Levels
                {
                    If (LNotEqual (OSYS, 0x07DC))
                    {
                        Return (PLVL)
                    }
                    Else
                    {
                        Return (PLV2)
                    }
                }

                Method (_BCM, 1, NotSerialized)  // _BCM: Brightness Control Method
                {
                    If (IGDS)
                    {
                        Store (LVLS (Arg0), Local1)
                        Store (Local1, ^^^LPCB.EC0.BRTS)
                        AINT (One, Arg0)
                    }
                    Else
                    {
                        Store (^^^PEG0.VGA.LCD.LVLS (Arg0), Local1)
                        Store (Local1, ^^^LPCB.EC0.BRTS)
                    }

                    Store (Arg0, BRTL)
                }

                Method (_BQC, 0, NotSerialized)  // _BQC: Brightness Query Current
                {
                    Return (BRTL)
                }
            }
(...)
```

Maybe the only solution is to modify the default AML, but I'd like to know if there's a simpler way.


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## asteriskRoss (Aug 7, 2014)

If you're using X.Org have you tried the xbacklight utility?  It takes the percentage increase or decrease in brightness as a parameter.  Within a desktop manager you could map the brightness keys to a call to xbacklight.


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## enriquefynn (Aug 7, 2014)

asteriskRoss said:
			
		

> If you're using X.Org have you tried the xbacklight utility?  It takes the percentage increase or decrease in brightness as a parameter.  Within a desktop manager you could map the brightness keys to a call to xbacklight.



Even if xbacklight works (it doesn't), I can't map the brightness keys, because they don't reach X, ACPI consumes them right away.


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