Testing And Debugging Tips

Testing and Debugging Tips

First - read the main wiki.

After you have successfully gotten your system up and running using the code in the drm-next-4.7 branch it will certainly be helpful to test and assist in any debugging any problems that arise. Here is some useful information to help with this process.

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Reporting Problems

1. First make sure you check the section bellow titled Common configuration issues to make sure you have configurd your environment correctly.

2. Check for pre-existing issues that match you problem here: Issues

3. If you do not see an existing issue please provide a descriptive but report via this repos [Issues] (https://github.com/FreeBSDDesktop/freebsd-base-graphics/issues) portal.

   • Ensure you provide the output of uname -a as well as your hardware architecture via the output of sysctl hw.model

4. Attach any pertinent backtraces or log files as documented above in the "Triaging Panics" section.

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Common configuration issues:

1. Ensure the user launching Xorg is a member of the video group, otherwise you will not have access to /dev/drm/ devices.

2. This sysctl knob will increase the likelihood that you can capture a kernel panic. This is because reliably transitioning to ddb in a panic caused by a driver bug is not something one can count on:

   debug.debugger_on_panic=0

3. This should also help you catch a core for analysis as well. Set the following in /boot/loader.conf

   dev.drm.skip_ddb="1"

4. The following can be useful for providing context and can be set in loader.conf to ensure debug output remains enabled The one problem with it is that debug output will slow things down enough to mask many problems.:

   dev.drm.drm_debug_persist=1

5. This can be changed at run-time. -1 is equivalent to setting all the debug flags.

   dev.drm.drm_debug=-1

6. set vblank_mode=0 when testing glxgears like so:

   $ export vblank_mode=0 && glxgears