[Mesa-dev] [PATCH 1/2] gbm: Enable DRI2 fence extension in the GBM DRI backend

Philipp Zabel p.zabel at pengutronix.de
Thu May 26 10:28:14 UTC 2016

Hi Emil,

Am Mittwoch, den 25.05.2016, 23:42 +0100 schrieb Emil Velikov:
> Or in other words, in case of egl + gbm, egl inherits the screen from
> the gbm device. As such platform_gbm does not call the core egl setup
> function, dri2_create_screen (like everyone else does x11, wayland...)
> but only the follow-up dri2_setup_screen.

Thank you for the explanation. What is the reason for this indirection?

> That said this patch will break things when using old libgbm and new
> libEGL and vice-versa. Sadly there's no way around it atm.
> Thus can we get an ABI check so that in the future we printout a
> message and abort early, instead of crashing in spectacular ways down
> the line?

I didn't think of that. How do you envision this ABI check to look like?
gbm(_drm)_device currently don't have any version fields and I'm not
sure how a new gbm backend would check for an old libEGL.
The first thing that comes to mind is a simple ABI version number to be
incremented in lock-step between libgbm and libEGL.


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