Comment 5 for bug 1267281

Revision history for this message
TraceyC (grrlgeek) wrote : Re: Auto-detection of a monitor being added or removed not working

I've tested with the latest Ubuntu and Xubuntu nightly live USB images. This is the first I had heard of those, and I'm very glad they are now available, specifically for cases like this. Here are my results.

---------------Monitor setup---------------
Laptop 1920 x 1080
Left external 1920 x 1200 (right of laptop)
Right external 1920 x 1200

---------------Ubuntu---------------
Booted docked with 2 ext monitors attached - success. Multiple monitors supported with display extended (rather than mirrored). This is the desired result.

Undocked
Windows correctly put on laptop display. This is the desired result.

Re-docked
Displays correctly detected, restored with correct placement
Windows returned to external monitor. This is the desired result.

---------------Xubuntu---------------
Booted docked
All monitors successfully detected, but displays mirrored rather than extended. Resolution of external monitors incorrectly set to be the same as the laptop resoluion.
Went to Display settings to correct
DP2 right of laptop - asked to keep settings but not done (clicked Keep)
Set correct resolution - asked to keep settings but not done (clicked Keep)
DP3 right of (laptop automatically selected) - asked to keep settings but not done (clicked Keep)
DP3 right of DP2 - asked to keep settings but not done (clicked Keep)
Set correct resolution - asked to keep settings (clicked Keep)

Display was finally extended across all monitors with proper resolution.

Undocked - Display was set only on the laptop as expected, but X became unresponsive before windows were moved to that display. Mouse movement was responding slowly & erratically.

I waited a few minutes, but the situation did not change.
I was able to get to a virtual terminal, eventually, with Ctrl-Alt-F1. I saw that kworker 0:2 was at 100% CPU utilization. Waited a few minutes & went back to X with Ctrl-Alt-F7. The laptop screen had white noise, the two external monitors had no display.

Also, when booting into the live Xubuntu USB environment, after settings proper resolutions but *not* undocking, I saw similar corruption during a reboot. The laptop display again showed the white noise / lines when the external monitors showed the Xubuntu logo screen.