[Mesa-dev] [PATCH v3 0/3] Software rendering in EGL-DRM

Pekka Paalanen ppaalanen at gmail.com
Thu Jul 3 02:24:44 PDT 2014

On Thu, 3 Jul 2014 10:48:26 +0200
Boris BREZILLON <boris.brezillon at free-electrons.com> wrote:

> Hello Giovanni,
> I have recently been working on a DRM/KMS driver which does not support
> OpenGL rendering (it only provides plane composition functionalities):
> [1].
> If I understand correctly you patch series might solve some of the
> issues I am facing.
> I'm trying to get wayland working with HW cursor and several planes,
> the problem is that it depends on GBM to provides drm plane and drm
> cursor support.

Which compositor? All the dependencies are in the compositors, not
Wayland per se.

If it is Weston, have you tried --use-pixman to avoid EGL altogether?
I see Weston still tries to use GBM for cursor fbs, while primary fbs
are dumb buffers, but then again, I'm not sure if cursors are supposed
to support dumb buffers.

Weston's overlay planes code however totally depends on EGL to provide
hw-capable buffers from clients. A software renderer support in EGL-DRM
won't help in that.


> I tried to get EGL working with my DRM device and it always ask for an
> atmel-hlcdc_dri.so module (I have applied this patch [2] to get to this
> point).
> First of all, am I mistaken in thinking this series could solve my
> issue ?
> If not, could you tell me on which branch (or which tag) you based
> your work ?
> I'm asking this because I tried to apply your patches on top of the
> master branch (a few days ago), and after fixing some conflict I got a
> segfault (sorry, I don't have the backtrace anymore :-(, but this was
> related to negative stride value which was implying faulty memory
> access).
> Yesterday I tried to rebase your patches on top of last master branch
> modifications, and it seems they've completely rework the gallium dri
> module architecture ([3]) and know I get an 'undefined symbol:
> dd_create_screen' error when mesa tries to load kms_swrast_dri.so.
> Sorry if my questions seem stupid to you, but I'm new in graphic
> related developments :-).
> Best Regards,
> Boris
> [1] https://lkml.org/lkml/2014/6/9/487
> [2] http://thread.gmane.org/gmane.comp.video.mesa3d.devel/66385
> [3] http://thread.gmane.org/gmane.comp.video.mesa3d.devel/78175

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