Can't switch display mode more than one cycle when docked
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Invalid
|
Undecided
|
Timo Aaltonen | ||
Trusty |
Fix Released
|
Undecided
|
Unassigned |
Bug Description
[Impact]
We have a system under certification that needs a workaround in the kernel for now. The bug is that if the machine is booted attached to a dock with a monitor connected to it's VGA output, the connection to the monitor is dropped after one full cycle of display modes with the hotkey combo. This is a firmware bug and will eventually be fixed by the BIOS vendor, but in the meantime we need a workaround in the kernel.
The dock has a builtin DP-VGA dongle which is the culprit here.
[Test Case]
attach the unit to a doc with a monitor plugged to a VGA port, switch display modes with hotkey combo, should be able to do more than one cycle with the combo
[Regression Potential]
We got the patch from Intel, with this disclaimer:
"The workaround in comment 41# maybe has side effect on DP port which doesn't connect DP screen. On these DP ports, this workaround will add an extra power on and power off command . So this workaround couldn't push to upstream."
so there shouldn't be any visible regressions..
CVE References
affects: | xorg (Ubuntu) → linux (Ubuntu) |
Changed in linux (Ubuntu): | |
assignee: | nobody → Timo Aaltonen (tjaalton) |
status: | New → Triaged |
Changed in linux (Ubuntu): | |
status: | Triaged → Fix Committed |
Changed in linux (Ubuntu Trusty): | |
status: | New → Fix Committed |
tags: |
added: verification-done-trusty removed: verification-needed-trusty |
Changed in linux (Ubuntu): | |
status: | Fix Committed → Invalid |
This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification- needed- trusty' to 'verification- done-trusty' .
If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.
See https:/ /wiki.ubuntu. com/Testing/ EnableProposed for documentation how to enable and use -proposed. Thank you!