[Nouveau] Nouveau fails to initialize G94GL / Quadro-FX1800 on aarch64 board

[Clemens Eisserer]

Hi again,

Some further digging revealed that NVPlatformProbe is called with the
flag PLATFORM_PROBE_GPU_SCREEN, so the flag XF86_ALLOCATE_GPU_SCREEN
is passed to xf86AllocateScreen.

After xf86AllocateScreen I end up with xf86GPUScreens == 1 and
xf86NumScreens == 0.

The xf86GPUScreens seems to be ignored by all the following code, only
xf86NumScreens is evaluated afterwards in xf86BusConfig:
    /* If nothing was detected, return now */
    if (xf86NumScreens == 0) {
        xf86Msg(X_ERROR, "No devices detected.\n");
        return FALSE;
    }

Is the issue that xf86NumScreens is zero at the beginning, or that
xf86GPUScreens is not taken into account later on?

Any help would be highly appreciated.

Thanks and best regards, Clemens