ACPI Fix (For https://github.com/Bumblebee-Project/Bumblebee/issues/764#issuecomment-559186316)

ssdt_15.dsl

Method (_ON, 0, Serialized)  // _ON_: Power On
{
    If ((OSYS >= 0x07DC))
    {
        \_SB.PCI0.PGON (Zero)
        If ((GPRF != One))
        {
            VREG = VGAB /* \_SB_.PCI0.PEG0.PEGP.VGAB */
        }
    }

    Return (Zero)
}

Method (_OFF, 0, Serialized)  // _OFF: Power Off
{
    If ((OSYS >= 0x07DC))
    {
        If ((GPRF != One))
        {
            VGAB = VREG /* \_SB_.PCI0.PEG0.PEGP.VREG */
        }

        \_SB.PCI0.PGOF (Zero)
    }

    Return (Zero)
}

ssdt_16.dsl

Method (_ON, 0, Serialized)  // _ON_: Power On
{
    \_SB.PCI0.PGON (Zero)
    Notify (\_SB.PCI0.PEG0, Zero) // Bus Check
}

Method (_OFF, 0, Serialized)  // _OFF: Power Off
{
    \_SB.PCI0.PGOF (Zero)
    Notify (\_SB.PCI0.PEG0, Zero) // Bus Check
}

ssdt_merged.dsl

DefinitionBlock ("", "SSDT", 0, "LEO", "Linux  ", 0x00001001)
{
    External (_SB_.PCI0.PEG0, DeviceObj)
    External (_SB_.PCI0.PEG0.PEGP, DeviceObj)
    External (_SB_.PCI0.PEG0.PEGP.GPRF, IntObj)
    External (_SB_.PCI0.PEG0.PEGP.VREG, FieldUnitObj)
    External (_SB_.PCI0.PEG0.PEGP.VGAB, BuffObj)
    External (_SB_.PCI0.PGOF, MethodObj)    // 1 Arguments
    External (_SB_.PCI0.PGON, MethodObj)    // 1 Arguments
    External (OSYS, IntObj)

    Scope (\_SB.PCI0.PEG0.PEGP)
    {
        Method (_ON, 0, Serialized)  // _ON_: Power On
        {
            Store("----Custom Card Power ON----", Debug)
            If ((OSYS >= 0x07DC))
            {
                \_SB.PCI0.PGON (Zero)
                Notify (\_SB.PCI0.PEG0, Zero) // Add from SSDT16
                If ((GPRF != One))
                {
                    VREG = VGAB /* \_SB_.PCI0.PEG0.PEGP.VGAB */
                }
            }

            Return (Zero)
        }

        Method (_OFF, 0, Serialized)  // _OFF: Power Off
        {
            Store("----Custom Card Power OFF----", Debug)
            If ((OSYS >= 0x07DC))
            {
                If ((GPRF != One))
                {
                    VGAB = VREG /* \_SB_.PCI0.PEG0.PEGP.VREG */
                }

                \_SB.PCI0.PGOF (Zero)
                Notify (\_SB.PCI0.PEG0, Zero) // Add from SSDT16
            }

            Return (Zero)
        }
    }
}