Troubleshooting

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Revision 48 as of 2012-04-13 23:47:38
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Revision 64 as of 2017-11-18 18:25:00
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Comment: 1) Mention xdiagnose install. 2) Reorder as folks may stop reading once reported. 3) RM general reporting as its distracting.
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#start
For hard bugs the analysis phase is the most important, and most challenging part of bug work. Depending on how the bug is behaving, there are multiple directions to investigate the issue. Here's some different approaches:
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 * [[X/Troubleshooting/Resolution|Resolution issues]]
 * [[X/Troubleshooting/HighCPU|High CPU issues]]
= 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 [[https://help.ubuntu.com/community/ReportingBugs|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
 * [[https://help.ubuntu.com/community/BootOptions|Boot Options]]
 * [[DebuggingKernelBoot|Debugging Kernel Boot Problems]]

Display Issues
 * [[X/Troubleshooting/3D|3D / GLX corruption and other issues]]
 * [[Kernel/Debugging/Backlight|Backlight issues]]
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 * [[X/i8xxUnsupported|i855 is Unsupported]] - Explanation of why i845, i855, i865, etc. chips aren't supported
 * [[X/Troubleshooting/HugeFonts|Fonts displayed way too big]]
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 * [[X/Troubleshooting/SingleColorScreen|Single color (brown/blue/etc.) screen on startup]]
 * [[X/Troubleshooting/HugeFonts|Fonts displayed way too big]]
 * [[X/Troubleshooting/XServerCrashOnResume|xserver crash on resume]]
 * [[X/Troubleshooting/OnlyLoadsVesa|Only loads vesa instead of correct driver]]
 * [[X/Troubleshooting/FglrxInteferesWithRadeonDriver|Switching between -fglrx and -ati drivers]]
 * [[X/Troubleshooting/NvidiaDriverSwitching|Switching between -nvidia and -nouveau drivers]]
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 * [[X/Troubleshooting/HalBreaksKeyboardAndMouse|Keyboard and mouse quit working]]  * [[X/MonitorDetection|Monitor detection]]
 * [[X/Troubleshooting/Resolution|Resolution detection]]
 * [[X/Troubleshooting/VideoDriverDetection|Video driver detection]]

General Issues
 * [[X/Glossary|Glossary]] - Common error messages and terminology
 * [[X/Troubleshooting/HighCPU|High CPU usage issues]]
 * [[X/Troubleshooting/HighMemory|High memory usage issues]]
 * [[X/Bugs/Transitions|X Transitions]] - Explanation for "installing xserver-xorg-core would break existing software"
 * [[X/Troubleshooting/XError|Program received an X Window System error]]
 * [[DebuggingKernelSuspend|Suspend and Resume issues]]

Input Issues
 * [[DebuggingKeyboardDetection|Keyboard detection]]
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 * [[X/Troubleshooting/XError|Program received an X Window System error]]
 * [[X/Troubleshooting/NvidiaDriverMissingKernelDriver]]
 * [[X/MonitorDetection|Monitor Detection problems]]
 * [[DebuggingTouchpadDetection|Touchpad detection]]
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 * [[X/Troubleshooting/Other|Other common issues...]] = Reporting a confirmed X bug to Launchpad =
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== Troubleshooting Kernel Modesetting Issues == == Initial filing of the report ==
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The {{{drm.debug=0x04}}} kernel option can be used to get additional debugging data included in your {{{dmesg}}} output. First, please install the package xdiagnose.

Next, ensure you click the Yes button for attaching additional debugging information after running the following via a terminal:
{{{
ubuntu-bug xorg
}}}

== Include developer information in your report ==

One will want to answer the following questions in order for a developer to address the issue:
 * 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 =

 * [[X/NonGraphicalBoot|Non-Graphical Booting]] - Running X manually, without a display manager (like lightdm, kdm, gdm...)
 * [[X/Debugging/WirelessWithoutX|Wireless Without X]] - How to get a wireless network connection without X.
 * [[X/Debugging/WiredWithoutRouter|Direct Wired Without WAP]] - How to connect two laptops with direct ethernet cord.

Crashes and Freezes
 * [[X/Backtracing|X Backtracing]] - How to collect a backtrace for an X crash
 * [[X/InterpretingIntelGpuDump|Interpreting GPU Dumps]] - Ringbuffers, batchbuffers, and the meaning of `intel_gpu_dump` output
 * [[X/DebuggingWithValgrind|Valgrind]] - Debugging memory leaks

Other Techniques
 * [[X/Dev/DeviceTreeHWDetection|Device Tree]]
 * [[X/Bisecting|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 [[https://wiki.ubuntu.com/X/Triaging|here]] for more on triaging X bugs, and [[https://wiki.ubuntu.com/X/Tagging|here]] for tagging.

= Fixing an X crash =

 * For more on this, please see [[https://wiki.ubuntu.com/X/FixingCrashes|here]].
 * [[X/Quirks|X Quirks]] - Fixes for some common hardware-specific issues.

= Other Resources =

 * [[https://help.ubuntu.com/community/Video|Video Resources]] at help.ubuntu.com
 * For installing [[https://help.ubuntu.com/community/BinaryDriverHowto/AMD|fglrx]] or [[https://help.ubuntu.com/community/BinaryDriverHowto/Nvidia|nvidia]] proprietary drivers.

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

Display Issues

General Issues

Input Issues

Reporting a confirmed X bug to Launchpad

Initial filing of the report

First, please install the package xdiagnose.

Next, ensure you click the Yes button for attaching additional debugging information after running the following via a terminal:

ubuntu-bug xorg

Include developer information in your report

One will want to answer the following questions in order for a developer to address the issue:

  • 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

Crashes and Freezes

Other Techniques

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


CategoryDebugging

X/Troubleshooting (last edited 2017-11-18 18:25:00 by penalvch)