Getting-Started-With-ACPI/Laptops/backlight-methods/manual.md

Fixing Backlight: Manual

• Finding the ACPI path
• Edits to the sample SSDT
• Compiling the SSDT
• Wrapping up

Finding the ACPI path

For this guide, we're gonna assume Windows is already on this laptop, as otherwise creating this SSDT is a bit more difficult.

Now open DeviceManager, and head to the following:

Device Manager -> Display Adapters -> Properties -> Details > BIOS device name

• Note some GPU ACPI pathing may be hiding under "BIOS device name"

From the above example, we can see our display is hooked up to PCI0.GFX0

Edits to the sample SSDT

Now that we have our ACPI path, lets grab our SSDT and get to work:

• SSDT-PNLF.dsl
• SSDT-PNLFCFL.dsl
  • For Coffee Lake and newer

By default, this uses PCI0.GFX0 for the pathing. you'll want to rename accordingly. For this example, we'll assume your pathing is PCI0.GPU0:

Before:

External (_SB_.PCI0.GFX0, DeviceObj) <- Rename this

Scope (_SB.PCI0.GFX0) <- Rename this

Device(_SB.PCI0.GFX0.PNLF) <- Rename this

Following the example pathing we found, the SSDT should look something like this:

After:

External (_SB_.PCI0.GPU0, DeviceObj) <- Renamed

Scope (_SB.PCI0.GPU0) <- Renamed

Device(_SB.PCI0.GPU0.PNLF) <- Renamed

Compiling the SSDT

With the SSDT done, you're now ready to compile the SSDT!

Wrapping up

Once you're done making your SSDT, either head to the next page to finish the rest of the SSDTs or head here if you're ready to wrap up:

• Cleanup