# Dell Studio 1558 Screen Brightness Driver in Kernel

## dman777

I'm having trouble finding the diver in the kernel that will allow me to adjust the screen brightness on my Dell Laptop 1558. Does anyone know what it is called?

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## Uranium

Hello,

this might sound unintuitive, but I had to enable ACPI_VIDEO (under Power management -> ACPI) for the brightness control to work on my Studio 1555. DELL_LAPTOP (Device drivers -> X86 Platform Specific Device Drivers) is probably needed as well (to access this option, you will have to enable DCDBAS and BACKLIGHT_CLASS_DEVICE)

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## dman777

Didn't help.... I found this from an Ubuntu bug #56811:

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/568611

"I have developed a PRELIMINARY TEST FIX for this problem, which is caused by a dysfunctional ACPI _BCM backlight brightness control method in the Dell Studio 1558 firmware (and likely the other 155x models). The fix involves overriding the use of the _BCM method with the Intel GPU i915 driver's opregion backlight control method. The fix will therefore affect all i915-based systems that support the opregion method not just Dell Studio systems. This does fix the brightness keys on the Dell Studio 1558 and might also fix other i915 systems with backlight brightness control problems."

How would I go about requesting this fix/patch get ported to the Gentoo kernel?

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## DaggyStyle

 *dman777 wrote:*   

> Didn't help.... I found this from an Ubuntu bug #56811:
> 
> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/568611
> 
> "I have developed a PRELIMINARY TEST FIX for this problem, which is caused by a dysfunctional ACPI _BCM backlight brightness control method in the Dell Studio 1558 firmware (and likely the other 155x models). The fix involves overriding the use of the _BCM method with the Intel GPU i915 driver's opregion backlight control method. The fix will therefore affect all i915-based systems that support the opregion method not just Dell Studio systems. This does fix the brightness keys on the Dell Studio 1558 and might also fix other i915 systems with backlight brightness control problems."
> ...

 

easy, open a bug request  :Smile: 

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## dman777

Bug #374435 filed. But I don't think anyone has looked at it yet.

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## DaggyStyle

 *dman777 wrote:*   

> Bug #374435 filed. But I don't think anyone has looked at it yet.

 

patience grasshopper...

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