[Bug 84718] DP MST: re-docking messes up displays

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=84718

--- Comment #16 from Daniel Michalik <dev at blackamp.de> ---
I understand your reasoning about the last bit I reported. I don't think it is
worth taking it up with Xfce to change the current behaviour, I can live with
that one just fine by reconfiguring screens when something is unplugged/plugged
in. 

I am still confused though why disabling a 'never-been-used' output should
change the framebuffer size. I think this does not happen with non-MST outputs.
Do you think this should be filed as an xrandr bug? 

Do you have any comment to the actual crash? Sorry for the 110 MB Xlog. ;) The
session was just two minutes long or so, but starting at 320 everything goes
haywire. I think it is connected to a timing issue, let me elaborate. Undocking
causes a drm udev event which calls a shell-script. The first thing this does
is to query /sys/class/drm/*/status to find out what the new configuration
looks like, and then calls a handful of xrandr queries. Nothing else, and none
of that should be able to cause a crash. 

What if /sys/class/drm/*/status of the MST ports is queried before they are
removed/updated? It looks like, from the log, as if it happens instantaneous
only for DP-5, but DP-3 and  DP-4 follow a few seconds later, that could be
just enough time for my script to try to query them in-between. Interesting
enough, if I disable the udev triggering, undock, wait 10s, and then execute
the script manually, it never seems to fail. Small number statistics,
admittedly.

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
You are on the CC list for the bug.
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20141009/033649a5/attachment.html>