Identifying if the issue is a bug or not

If you aren't sure if you have encountered a software bug in Ubuntu, then you would want to seek help in determining if the issue is a bug or not from here.

If you have confirmed the issue is a bug, please read on.

Determining which type of bug you have

Not all bugs where X seems to be the root cause are in fact an X related bug. Hence, here is documentation on potential root causes:

Booting

• Boot Options

• Debugging Kernel Boot Problems

Display Issues

• 3D / GLX corruption and other issues

• Backlight issues

• Blank Screen on startup issues

• i855 is Unsupported - Explanation of why i845, i855, i865, etc. chips aren't supported

• Fonts displayed way too big

• Freeze issues

• Intel graphics performance issues

• Monitor detection

• Resolution detection

• Video driver detection

General Issues

• Glossary - Common error messages and terminology

• High CPU usage issues

• High memory usage issues

• X Transitions - Explanation for "installing xserver-xorg-core would break existing software"

• Program received an X Window System error

• Suspend and Resume issues

Input Issues

• Keyboard detection

• Multimedia hotkey problems

• Touchpad detection

Reporting a confirmed X bug to Launchpad

Initial filing of the report

First, one will want to familiarize themselves with how to report bugs effectively as per here.

Once this is reviewed, please file a new bug report with Ubuntu via a terminal:

ubuntu-bug xorg

Please ensure you have the package xdiagnose installed, and that you click the Yes button for attaching additional debugging information.

Including enough information for a developer to work on it

One will want to answer the following questions:

• Does the report include debugging information from the relevant article relating to the reported issue?
• Is this a regression?
• Does this happen in the latest version of Ubuntu?
• Does this happen in the latest version available from upstream?

Debugging techniques

• Non-Graphical Booting - Running X manually, without a display manager (like lightdm, kdm, gdm...)

• Wireless Without X - How to get a wireless network connection without X.

• Direct Wired Without WAP - How to connect two laptops with direct ethernet cord.

Crashes and Freezes

• X Backtracing - How to collect a backtrace for an X crash

• Interpreting GPU Dumps - Ringbuffers, batchbuffers, and the meaning of intel_gpu_dump output

• Valgrind - Debugging memory leaks

Other Techniques

• Device Tree

• X Bisecting - Using bisection techniques to solve regressions or backport fixes

• X/Testing/Touch - Touchscreen and multi-touch testing

Triaging and tagging X bugs

Please see here for more on triaging X bugs, and here for tagging.

Fixing an X crash

• For more on this, please see here.

• X Quirks - Fixes for some common hardware-specific issues.

Other Resources

• Video Resources at help.ubuntu.com

• For installing fglrx or nvidia proprietary drivers.

CategoryDebugging