Report it upstream

In most cases, it is preferrable to report the bug upstream at https://bugs.freedesktop.org/enter_bug.cgi?product=xorg

See https://01.org/linuxgraphics/documentation/how-report-bugs for a good introduction on how to write useful bug reports. While the document is targeted at Intel graphics hardware, it is a good guideline for other vendor’s hardware as well.

Simple as reportbug

Initial report

Unless you know which package to report the bug against, you can report the bug against the xorg metapackage:

reportbug xorg

Like most packages related to the X server, reporting a bug against this package triggers a bug script which is going to collect X-related information, be it installed packages, running kernel, X configuration, X log, and so on.

Note

In case this metapackage wasn’t used to install your X stack, report a bug against xserver-xorg instead. And if that one isn’t installed either, go for xserver-xorg-core.

If a backtrace shows up in the X log, it’s much appreciated to try and get a full backtrace using gdb.

Follow-up with more info

If you reported a bug against another package and if that bug was reassigned to an X-related package, we might need more information. You can run the bug script manually and attach its output to your mail to the bug report:

/usr/share/bug/xserver-xorg-core/script 3>/tmp/script.log
Note

Make sure there’s no space between 3 and >, that’s a shell redirection.