[Mesa-dev] Exposing (or lack of) EGL device support on platforms lacking DRM devices (Was Re: [Piglit] [PATCH 1/2] egl: Add sanity test for EGL_EXT_device_query (v3))

[Emil Velikov]

On 6 September 2016 at 18:32, Mathias Fröhlich
<Mathias.Froehlich at gmx.net> wrote:

>>  * Systems with fb only, disabled render nodes and/or alike.
>> EGL implementations (in our case the libdrm API provides all the info
>> about available DRM devices) can effectively detect the presence of
>> HW/SW devices and expose relevant extensions.
>> Note: The presence does not and _cannot_ imply that one will always
>> succeed using each device.
> So you are saying, on a system without drm device we should return a more or
> less dead single EGLDeviceEXT from eglQueryDevicesEXT(...).

Nope. What I'm saying is that if the system lacks any DRM devices (or
the devices lack any specifics) the respective device extension(s)
won't be exposed.

Regardless if SW device is available or not there a caveat - you
simply cannot say that using device X will work. This is what the note
is about - a simple disclaimer.

Regards,
Emil