Re: non-PCI driver name lookup

[maya%netbsd.org@localhost]

On Sun, Jul 07, 2019 at 11:23:14PM +0100, Robert Swindells wrote:
> 
> The pinebook uses the modesetting X11 driver.
> 
> An application that calls DRI2Connect() doesn't get back valid values
> for device name and driver name so typically assumes that DRI2 isn't
> available.
> 
> This looks to be down to how libdrm tries to work out which driver is
> being used from an open file descriptor. I presume the NetBSD specific
> code in it does work for PCI devices but it looks like we need to add
> something for display devices that are built into the CPU.
> 
> 

I assume, although I can't find proof that it's the case, that you want
to adjust the 'unique' value.

arm/nvidia/tegra_nouveau.c
257:	master->unique = kmem_asprintf("platform:tegra_nouveau:%02d", id);

I think the code in libdrm looks at this value via DRM_IOCTL_GET_UNIQUE,
but I'm not sure.