On Tue, 15 Sep 2015, Lucas Tanure tanure@linux.com wrote:
Hi,
I would like to start to contribute to drm part of kernel. I tried a few things:
- Compiled linux-next tree using C=1 (sparse) to find things to improve.
But couldn't find any problem or issue.
- I looked in "www.x.org/wiki/DRMJanitors/" for stuff to do, but seems that
most of them are already done when I checked the code.
- Compiled and run the linux-next tree to test the code. And for this I got
the warning below. I tried to compile a few older versions of linux-next in order to find the offending commit. But I didn't succeed, many commits don't boot at all, and is difficult to get more information about the status of the warning for that version.
I think especially for getting started linux-next is too volatile. I'd go for Linus' git master first. After that, I'd still recommend driver specific trees rather than linux-next.
drm/i915 branches are at http://cgit.freedesktop.org/drm-intel
So, I would like some tips about how to debug DRM code, how to test, how to get more information about issues. What I do is :
- Compile and run
- Restart to a good kernel
- "journalctl --boot=-1" to see if I got any warning on previous kernel
Also, if any developer needs/wants some help and it's ok to guide a new guy in DRM code, I would like to get help about tasks to do, things to clean/improve. I'm reading https://www.kernel.org/doc/htmldocs/drm/ to start, and I have done a few courses from linux foundation.
It's pretty hard to give generic advise; what works for me doesn't necessarily work for you. With that out of the way, try focusing on some detail and figure out how it works. Or find an itch and scratch it, maybe a bug you experience. Or a bug someone else has and you can reproduce it (product "DRI" at https://bugs.freedesktop.org/, you'll probably need to narrow the search down). Expand on related details, etc.
Based on the warn you seem to have an Intel GPU, so you might find https://01.org/linuxgraphics/documentation helful.
You might also get faster replies on IRC at #dri-devel and #intel-gfx on freenode, as long as you don't bug people too much. ;)
HTH, Jani.