[Mesa-dev] [RFC] GLX_MESA_query_renderer

[Christoph Bumiller]

On 02.03.2013 00:14, Ian Romanick wrote:
> Since last September I've been gradually working on an extension to
> let applications query information about the renderer before (and
> after) creating a context.  I've talked it over with a few ISVs and
> with various other folks.  I also gathered some input from folks at
> FOSDEM after my talk there.  After going through several iterations of
> review and modification, I think it's finally ready for wider input.
>
> Some of the earliest feedback that I got was that many ISVs really
> like the interface that fills this niche on Mac OS.  It's a pretty
> nice API, and this API is modeled after it.  There are, however, some
> differences.
>
> I've pasted the spec below so that people can provide in-line
> comments.  I've also pushed a branch with the spec and the initial
> implementation.  There are a few things potentially provided by the
> spec that are not included in the initial implementation.  I've
> implemented a couple unit tests, and I have some piglit tests
> in-progress.
>
> http://cgit.freedesktop.org/~idr/mesa/log/?h=query-renderer
>
> I'm mostly looking for input on the specification itself.  Once this
> is good, I will also add EGL support.
...
>     GLX renderer attribute         number     description
>                                   of values
>     ----------------------        ---------   -----------
>     GLX_RENDERER_VENDOR_ID_MESA   1           PCI ID of the device vendor
>     GLX_RENDERER_DEVICE_ID_MESA   1           PCI ID of the device
>
...
>
>     5) How can applications tell the difference between different
> hardware
>     renderers for the same device?  For example, whether the renderer
> is the
>     open-source driver or the closed-source driver.
>
>         RESOLVED.  Assuming this extension is ever implemented outside
> Mesa,
>         applications can query GLX_RENDERER_VENDOR_ID_MESA from
>         glXQueryRendererStringMESA.  This will almost certainly return
>         different strings for open-source and closed-source drivers.
>

Why would the "PCI ID of the device vendor" change with the driver ?