[Mesa-dev] [PATCH 15/18] docs: Import extension spec for GLX_MESA_query_renderer

[Ian Romanick]

On 11/07/2013 01:22 PM, Dave Airlie wrote:
> On Sat, Oct 12, 2013 at 8:10 AM, Ian Romanick <idr at freedesktop.org> wrote:
>> From: Ian Romanick <ian.d.romanick at intel.com>
>>
>> The enumerated values are currently allocated from Intel's range.
> 
> Some highlevel comments below,
> 
> 
>> +    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
> 
> Okay PCI IDs might seem useful but we have a lot of situations where
> they aren't available,
> 
> a) ARM devices generally don't have them
> b) nvidia generally espouse using PCI IDs in favour of a chip family
> ID they bake into the GPUs,
> nouveau doesn't even know the actual PCI IDs in userspace, we could
> find them but it does take a bit more work, like new kernel interface.

Multiple ISVs, including Wine, asked specifically for PCI IDs.  If a PCI
ID doesn't exist or can't be provided... zero for the
GLX_RENDERER_DEVICE_ID_MESA?  It should always be possible to provide a
reasonable value for GLX_RENDERER_VENDOR_ID_MESA.  I can add an issue
for that and adjust the documentation of those queries.

Does that sound reasonable?

>> +
>> +    GLX renderer attribute        description
>> +    ----------------------        -----------
>> +    GLX_RENDERER_VENDOR_ID_MESA   Name of the renderer provider.  This may
>> +                                  differ from the vendor name of the
>> +                                  underlying hardware.
>> +    GLX_RENDERER_DEVICE_ID_MESA   Name of the renderer.  This may differ from
>> +                                  the name of the underlying hardware (e.g.,
>> +                                  for a software renderer).
>> +
>> +    If <attribute> is not a recognized value, NULL is returned, but no GLX
>> +    error is generated.
>> +
>> +    The string returned for GLX_RENDERER_VENDOR_ID_MESA will have the same
>> +    format as the string that would be returned by glGetString of GL_VENDOR.
>> +    It may, however, have a different value.
> 
> Any reason for the value to be different here? Like a use case?

Vendor and device are the only ones that make any sense to be strings.
Is there any utility in getting the memory size as a string? :)

>> +    14) Why not make the queries from issue #14 GL functions (instead of GLX)?
>> +
> 
> from issue 14? this is issue 14

Right... that should say "issue #13".

> Dave.