In the old days, there were not a lot of users of open-source 3D graphics drivers. Aside from a few ID Software games, tuxracer, and glxgears, there were basically no applications. As a result, we got almost no bug reports. It was a blessing and a curse.
Now days, thanks to Valve Software and Steam, there are more applications than you can shake a stick at. As a result, we get a lot of bug reports. It is a blessing and a curse.
There's quite a wide chasm between a good bug report and a bad bug report. Since we have a lot to do, the quality of the bug report can make a big difference in how quickly the bug gets fixed. A poorly written bug report may get ignored. A poorly written bug may require several rounds asking for more information or clarifications. A poorly written bug report may send a developer looking for the problem in the wrong place.
As someone who fields a lot of these reports for Mesa, here's what I look for...
Submit against the right product and component. The component will determine the person (or mailing list) that initially receives notification about the bug. If you have a bug in the Radeon driver and only people working Nouveau get the bug e-mail, your bug probably won't get much attention.
If you have experienced a bug in 3D rendering, you want to submit your bug against Mesa.
Selecting the correct component can be tricky. It doesn't have to be 100% correct initially, but it should be close enough to get the attention of the right people. A good first approximation is to pick the component that matches the hardware you are running on. That means one of the following:
- Any modern Intel GPU: Drivers/DRI/i965
- Old Intel GPUs like i915, i945, G33, or Pineview: Drivers/DRI/i915
- Any modern NVIDIA GPU: Drivers/DRI/nouveau.
- Any modern Radeon GPU: Either Drivers/Gallium/radeonsi or Drivers/Gallium/r600.
If you're not sure what GPU is in your system, the command
glxinfo | grep "OpenGL renderer string"will help.
Correctly describe the software on your system. There is a field in bugzilla to select the version where the bug was encountered. This information is useful, but it is more important to get specific, detailed information in the bug report.
Provide the output of
glxinfo | grep "OpenGL version string". There may be two lines of output. That's fine, and you should include both.
If you are using the drivers supplied by your distro, include the version of the distro package. On Fedora, this can be determined by
rpm -q mesa-dri-drivers. Other distros use other commands. I don't know what they are, but Googling for "how do i determine the version of an installed package on " should help.
If you built the driver from source using a Mesa release tarball, include the full name of that tarball.
If you built the driver from source using the Mesa GIT repository, include SHA of the commit used.
Include the full version of the kernel using
uname -r. This isn't always important, but it is sometimes helpful.
Correctly describe the hardware in your system. There are a lot of variations of each GPU out there. Knowing exactly which variation exhibited bad behavior can help find the problem.
Provide the output of
glxinfo | grep "OpenGL renderer string". As mentioned above, this is the hardware that Mesa thinks is in the system.
Provide the output of
lspci -d ::0300 -nn. This provides the raw PCI information about the GPU. In some cases this maybe more detailed (or just plain different) than the output from
Provide the output of
grep "model name" /proc/cpuinfo | head -1. It is sometimes useful to know the CPU in the system, and this provides information about the CPU model.
Thoroughly describe the problem you observed. There are two goals. First, you want the person reading the bug report to know both what did happen and what you expected to happen. Second, you want the person reading the bug report to know how to reproduce the problem you observed. The person fielding the bug report may not have access to the application.
If the application was run from the command line, provide the full command line used to run the application.
If the application is a test that was run from piglit, provide the command line used to run the test, not the command line used to run piglit. This information is in the piglit
If the application is game or other complex application, provide any necessary information needed to reproduce the problem. Did it happen at specific location in a level? Did it happen while performing a specific operation? Does it only happen when loading certain data files?
Provide output from the application. If the application is a test case, provide the text output from the test. If this output is, say, less than 5 lines, include it in the report. Otherwise provide it as an attachment. Output lines that just say "Fail" are not useful. It is usually possible to run tests in verbose mode that will provide helpful output.
If the application is game or other complex application, try to provide a screenshot. If it is possible, providing a "good" and "bad" screenshot is even more useful. Bug #91617 is a good example of this.
If the bug was a GPU or system hang, provide output from
dmesgas an attachment to the bug. If the bug is not a GPU or system hang, this output is unlikely to be useful.
Add annotations to the bug summary. Annotations are parts of the bug summary at the beginning enclosed in square brackets. The two most important ones are
bisected(see the next item for more information about
bisected). If the bug being reported is a new failure after updating system software, it is (most likely) a regression. Adding
[regression]to the beginning of the bug summary will help get it noticed! In this case you also must, at the very least, tell us what software version worked... with all the same details mentioned above.
The other annotations used by the Intel team are short names for hardware versions. Unless you're part of Intel's driver development team or QA team, you don't really need to worry about these. The ones currently in use are:
SKL- Skylake / GEN9
BDW- Broadwell / GEN8
BSW- Brasswell / lower power GEN8
HSW- Haswell / GEN7.5
BYT- Baytrail / lower power GEN7. There may still be some bugs with
VLV. This is from the older Valleyview name.
IVB- Ivy Bridge / GEN7
SNB- Sandy Bridge / GEN6
ILK- Ironlake / GEN5
GM45- Eaglelake / GEN4.5
965gmor similar - Broadwater / Crestline / GEN4
Bisect regressions. If you have encountered a regression and you are building a driver from source, please provide the results of git-bisect. We really just need the last part: the guilty commit. When this information is available, add
bisectedto the tag. This should look like
Note: If you're on a QA team somewhere, supplying the bisect is a practical requirement.
Respond to the bug. There may be requests for more information. There may be requests to test patches. Either way, developers working on the bug need you to be responsive. I have closed a lot of bugs over the years because the original reporter didn't respond to a question for six months or more. Sometimes this is our fault because the question was asked months (or even years) after the bug was submitted.
The general practice is to change the bug status to
NEEDINFOwhen information or testing is requested. After providing the requested information, please change the status back to either
ASSIGNEDor whatever the previous state was.
It is also general practice to leave bugs in the
NEWstate until a developer actually starts working on it. When someone starts work, they will change the "Assigned To" field and change the status to
ASSIGNED. This is how we prevent multiple people from duplicating effort by working on the same bug.
If the bug was encountered in a released version and the bug persists after updating to a new major version (e.g., from 10.6.2 to 11.0.1), it is probably worth adding a comment to the bug "Problem still occurs with ." That way we know you're alive and still care about the problem.
Here is a sample script that collects a lot of information request. It does
not collect information about the driver version other than the
output. Since I don't know whether you're using the distro driver or building
one from source, there really isn't any way that my script could do that.
You'll want to customize it for your own needs.
echo "Software versions:" echo -n " " uname -r echo -n " " glxinfo 2>&1 | grep "OpenGL version string" echo echo "GPU hardware:" echo -n " " glxinfo 2>&1 | grep "OpenGL renderer string" echo -n " " lspci -d ::0300 -nn echo echo "CPU hardware:" echo -n " " uname -m echo -n " " grep "model name" /proc/cpuinfo | head -1 | sed 's/^[^:]*: //' echo
This generates nicely formatted output that you can copy-and-paste directly into a bug report. Here is the output from my system:
Software versions: 4.0.4-202.fc21.x86_64 OpenGL version string: 3.0 Mesa 11.1.0-devel GPU hardware: OpenGL renderer string: Mesa DRI Intel(R) HD Graphics 5500 (Broadwell GT2) 00:02.0 VGA compatible controller : Intel Corporation Broadwell-U Integrated Graphics [8086:1616] (rev 09) CPU hardware: x86_64 Intel(R) Core(TM) i7-5600U CPU @ 2.60GHz