This patch is a BIOS/board specific fix-up for some Haswell machines, which have both HDMI and Display Port output but BIOS only enables first pair of audio codec pin & cvt by mistake.
If OEM vendor overrides the PCI SSID, this patch will not work.
If OEM or future Intel BIOS enables the pin & cvts properly according to board design, this patch is not needed.
Answer from Intel:
"Hi David and Xiong,
This patch is a BIOS/board specific fix-up for some Haswell machines, which have both HDMI and Display Port output but BIOS only enables first pair of audio codec pin & cvt by mistake.
If OEM vendor overrides the PCI SSID, this patch will not work.
If OEM or future Intel BIOS enables the pin & cvts properly according to board design, this patch is not needed.
Thanks
Mengdong"