maintainer-feedback requested: [Bug 214204] Unable to run OpenCL programs while X11 session is active

[bugzilla-noreply at freebsd.org]

Alexey Dokuchaev <danfe at FreeBSD.org> has reassigned Bugzilla Automation
<bugzilla at FreeBSD.org>'s request for maintainer-feedback to x11 at FreeBSD.org:
Bug 214204: Unable to run OpenCL programs while X11 session is active
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=214204



--- Description ---
I've decided to play with OpenCL on AMD A8-5550M APU laptop of mine a bit, so
I've read our wiki [1], installed necessary ports, googled for a simple OpenCL
program source code [2], built it, and run.

It ran OK, but only when I switched from my X11 session to console, or if I run
it as root.  Being inside X, it reports:

> radeon: Failed to get PCI ID, error number -13
> Using platform: Clover
>  No devices found. Check OpenCL installation!
devel/clinfo also behaves this way (finds no devices) and spits out the same
error.	My user belongs to "video" group, and permissions on /dev/dri/* are
sane (default, "rw-" for "video" group).

-13 indicates "permission denied" (-EACCES).  Apparently, similar (or perhaps
related) bug was discovered and fixed in Mesa back in 2012 [3].  The code in
current Mesa is different though.  Perhaps FreeBSD needs special treatment, or
original bug resurfaced.  I'm not an expert on Mesa codebase but will gladly
provide any additional details and happy to test patches.

[1] https://wiki.freebsd.org/Graphics/OpenCL
[2]
http://simpleopencl.blogspot.ru/2013/06/tutorial-simple-start-with-opencl-and-c
.html
[3] https://lists.freedesktop.org/archives/mesa-commit/2012-July/038068.html