*

Validating changes to KMS drivers with IGT

Tomeu Vizoso avatar

Posted on 21/04/2016 by Tomeu Vizoso

Share this post:

New DRM drivers are being added to almost each new kernel release, and because the mode setting API is so rich and complex, bugs do slip in that translate to differences in behaviour between drivers.

There have been previous attempts at writing test suites for validating changes and preventing regressions, but they have typically happened downstream and focused on the specific needs of specific products and limited to one or at most a few of different hardware platforms.

Writing these tests from scratch would have been an enormous amount of work, and gathering previous efforts and joining them wouldn't be much worth it because they were written using different test frameworks and in different programming languages. Also, there would be great overlap on the basic tests, and little would remain of the trickier stuff.

Of the existing test suites, the one with most coverage is intel-gpu-tools, used by the Intel graphics team. Though a big part is specific to the i915 driver, what uses the generic APIs is pretty much driver-independent and can be made to work with the other drivers without much effort. Also, Broadcom's Eric Anholt has already started adding tests for IOCTLs specific to the VideoCore-IV driver.

Collabora's Micah Fedke and Daniel Stone had added a facility for selecting DRM device files other than i915's and I improved the abstraction for creating buffers so it works for drivers without GEM buffers. Next I removed a bunch of superfluous dependencies on i915-only stuff and got a useful subset of tests to run on a Radxa Rock2 board (with the Rockchip 3288 SoC). Around half of these patches have been merged already and the other half are awaiting review. Meanwhile, Collabora's Robert Foss is running the ported tests on a Raspberry Pi 2 and has started sending patches to account for its peculiarities.

The next two big chunks of work are abstracting CRC checksums of frames (on drivers other than i915 this could be done with Google's Chamelium or with a board similar to Numato Opsis), and the buffer management API from libdrm that is currently i915-only (bufmgr). Something that will have to be dealt with in the future is abstracting the submittal of specific loads on the GPU as that's currently very much driver-specific.

Additionally, I will be scheduling jobs in our LAVA instance to run these tests on the boards we have in there.

Thanks to Google for sponsoring my time, to the Intel OTC folks for their support and reviews, and to Collabora for sponsoring Robert's, Micah's and Daniel's time.

 

Original post

Related Posts

Related Posts

Comments (0)


Add a Comment






Allowed tags: <b><i><br>Add a new comment:


Latest Blog Posts

Quick hack: Speed up your GitLab CI

06/11/2018

Did you know you could register your own PC, or a spare laptop collecting dust in a drawer, to get instant CI going on GitLab? Not only…

Introducing Zink, an OpenGL implementation on top of Vulkan

31/10/2018

For the last month or so, I've been playing with a new project during my work at Collabora, and as I've already briefly talked about at…

On the low adoption of automated testing in FOSS

18/10/2018

For projects of any value and significance, having a comprehensive automated test suite is nowadays considered a standard software engineering…

Recently in Geoclue

12/10/2018

After I started working for Collabora in April, I've finally been able to put some time on maintenance and development of Geoclue again.…

The beauty of Open Source

10/10/2018

Like all software, Open Source software isn't without it's bugs and issues. However, thanks to the nature of Open Source, resolving or mitigating…

MicroDebConf Brasilia

02/10/2018

Last month, the first "MicroDebConf" took place at the Gama campus of the University of Brasilia. Here's a look at how this one day event…

Open Since 2005 logo

We use cookies on this website to ensure that you get the best experience. By continuing to use this website you are consenting to the use of these cookies. To find out more please follow this link.

Collabora Ltd © 2005-2018. All rights reserved. Website sitemap.