[coreboot] KGPE-D16: Trouble using three PCIe cards simultaneously

[Alberto Bursi]

On 02/06/2018 22:03, Daniel Kulesz via coreboot wrote:
> Hi folks,
>
> maybe this is not really coreboot-related, but I am experiencing an issue with the KGPE-D16 that there seems to be no working constellation how the following three cards can be put into service:
>
> - nvidia GPU (PCIe 3 x16, takes 1 slot but occupies two)
> - ASUS hypercard (PCIe 3 x16, takes 1 slot, has four M.2 slot with PCIe x4 each), see [1]
> - USB3 controller card (PCIe x4, takes 1 slot)
>
> No matter what I try, the hypercard is unable to detect more than two M.2 ssds. And only in the following config:
>
> 1 (MIO): empty
> 2: GPU
> 3: (GPU)
> 4: Hypercard
> 5: empty
>
> When I put the USB3 card in 5, only one of the M.2 ssds on the hypercard is recognized. Therefore, I also tried swapping stuff in many combinations such as the following:
>
> 1: empty
> 2: Hypercard
> 3: empty
> 4: USB3
> 5: GPU
>
> But no matter what I do, there seems to be now way to get all three cards working simulaneously. Even with JUST the hypercard and nothing else it will only detect two of the three M.2 cards inserted. :/
>
> Seems like the vendor bios has the same issue. My plan now is to get a GPU that occupies only 1 slot and put the USB3 card next to it.
>
> Any help and clarifying explanations on this topic are warmly welcome.
>
> Cheers, Daniel
>
>
> [1] https://www.asus.com/Motherboard-Accessory/HYPER-M-2-X16-CARD/
>

It might need to be booted in UEFI mode to work, are you using tianocore 
payload (the UEFI payload) in your coreboot firmware on that board?

-Alberto