If your backlight has an issue after waking up from sleep you probably need to add the following to your dsdt file:
}
}
+ Device (PNLF)
+ {
+ Name (_HID, EisaId ("APP0002"))
+ Name (_CID, "backlight")
+ Name (_UID, 0x0A)
+ Name (_STA, 0x0B)
+ }
+
Device (PWRB)
{
Name (_CID, EisaId ("PNP0C0C"))
the full dsdt source code can be found on my github or just get the compiled dsdt.aml