Question: Issue with vainfo on multiple GPU systems on Linux

Hello there,

On a dual GPU system where the following conditions are met:

1. A discrete and an integrated GPU co-exist on the system, and are both enabled, and

2. Both DRI devices are present, under `/dev/dri/renderD128` and `/dev/dri/renderD129`

3. The primary renderer is set up as the discrete GPU, such that running:

`glxinfo | grep render `

Returns the identifier for the discrete GPU.

Running `vainfo`, with a preferred driver of choice set up in /etc/environment under the variables:

```
LIBVA_DRIVER_NAME=i965
LIBVA_DRIVERS_PATH=/usr/lib/x86_64-linux-gnu/dri

```
Where both libva and the vaapi drivers have been built and prefixed to /usr will definitely return a libva initialization error, as shown in the example below:

```
vainfo
libva info: VA-API version 0.40.0
libva info: va_getDriverName() returns 0
libva info: User requested driver 'i965'
libva info: Trying to open /usr/lib/x86_64-linux-gnu/dri/i965_drv_video.so
libva info: Found init function __vaDriverInit_0_40
libva error: /usr/lib/x86_64-linux-gnu/dri/i965_drv_video.so init failed
libva info: va_openDriver() returns -1
vaInitialize failed with error code -1 (unknown libva error),exit

```
Yet a tool such as FFmpeg will correctly initialize and encode via VAAPI if the proper render node (`/dev/dri/renderD128`, in my case) is passed.

Is there a way to bind vainfo to a specific render node, through an environment variable or a launch argument such that tools relying on VAAPI can return the correctly initialized device state, as FFmpeg does?

Regards,

Brainiarc7