[Mesa-dev] GLX extension for vendor name lookup in libglvnd

[Adam Jackson]

On Thu, 2016-03-10 at 10:53 -0700, Kyle Brenneman wrote:
> On 03/10/2016 10:47 AM, Martin Peres wrote:
> > 
> > That could be a hacky way of handling the case where multiple 3D 
> > drivers could be used to drive the same GPU. This may be necessary in 
> > the future if two mesa drivers support the same GPU but one is 
> > considered better than the other. We can also imagine a case where a 
> > proprietary driver would need to be co-installable with an open source 
> > one and would still use the same DDX. Isn't that what AMD is going to 
> > do soon? Did anyone think about this case?
> That case is the reason for allowing multiple vendor names. For a case 
> like AMD's driver, it would hand back two names. The order would be up 
> to the driver implementation, but I would guess that it would list the 
> proprietary driver first and the open source driver second. If the 
> proprietary one is installed, then the client would use it, and if not, 
> the client would use the open source one.

Right. It's pretty straightforward (and I plan) to wire this logic
through to xorg.conf, so the admin can control the list at server
startup time. Historically it's been somewhat pointless to do so, since
all the proprietary drivers have also replaced the server's GLX module,
but this gives us a path towards not doing that anymore at least.

I'd also considered using this mechanism as a starting path towards
both implementing GLX+Xinerama at all for the open drivers, and
eventually to do that with heterogeneous open/closed GLX on the server
side. Those are both fairly long term prospects, but I imagine it'll be
easier to do if we can opt into different client-side logic.

- ajax