ApolloLakeFspBinPkg[MR6] FSP-M PrimaryVideoAdaptor UPD possible values are wrong

[Th3Fanbus]

Hi,

Looks like the documented possible values for the FSP-M PrimaryVideoAdaptor UPD are not correct. The UPD headers state the following:
/** Offset 0x004C - Primary Display Select which of IGD/PCI Graphics device should be Primary Display. 0x0:AUTO(Default), 0x2:IGD, 0x3:PCI 0x0:AUTO, 0x2:IGD, 0x3:PCI **/ UINT8 PrimaryVideoAdaptor;

However, testing showed that any non-zero value will result in FSP setting the IVD (IGD VGA Disable) bit in the GGC register (PCI B:D.F 0:0.0 offset 0x50), regardless of whether another video card is present in the system. When PrimaryVideoAdaptor is zero, the IVD bit is cleared as well. Of course, this only happens if the IGD is enabled.

The simplest solution (and what I would prefer) is to simply update the UPD's description to match FSP's behavior, that is: 0x0:IGD, 0x1:PCI.

Thanks in advance,
Angel