[i915_bpo][SKL-U] System hangs when VGA monitor plugged in

[Timo Aaltonen]

A system being certified hangs hard when a VGA monitor is plugged in. The machine has a built-in DP MST bridge, but the driver has no support for MST. Upstream recently added a patch to add support for it, and it improves the situation that there's no hang anymore. Monitor still stays blank but that'll need another SRU once a patch for it is available.

[Timo Aaltonen (tjaalton)]

I've backported this commit:

commit e404ba8d06ff2a1bdb916a9e5d2c09cacd7e5ca3
Author: Ville Syrjälä <email address hidden>
Date: Mon Aug 17 18:46:20 2015 +0300

    drm/i915: Setup DDI clk for MST on SKL

    Set up the DDI->PLL mapping on SKL also for MST links. Might help make
    MST operational on SKL.

    v2: Rebased due to KBL
        Improve the patch subject, Jesse provided the new one

    Cc: Maarten Lankhorst <email address hidden>
    Signed-off-by: Ville Syrjälä <email address hidden>
    Link: http://patchwork.freedesktop<email address hidden>
    References: https://bugs.freedesktop.org/show_bug.cgi?id=91791
    Reviewed-by: Jesse Barnes <email address hidden>

for our i915_bpo driver, and it has been tested to fix the hang.

[Timo Aaltonen (tjaalton)]

(origin is drm-intel-next-queued from git://anongit.freedesktop.org/drm-intel)

[Leon Liao (lihow731)]

The system hung issued is fixed in the -32.37+bpo2.1 and -34.39+bpo1 kernel.

[Brad Figg (brad-figg)]

This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:

apport-collect 1515169

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Luis Henriques (henrix)]

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-vivid' to 'verification-done-vivid'.

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!

[Leon Liao (lihow731)]

I verified the proposed kernel 3.19.0-36-generic.
The system is not hung after plugged the VGA monitor.

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 3.19.0-37.42

---------------
linux (3.19.0-37.42) vivid; urgency=low

  [ Kamal Mostafa ]

  * Release Tracking Bug
    - LP: #1518406

  [ K. Y. Srinivasan ]

  * SAUCE: Drivers: hv: vmbus: Fix a Host signaling bug
    - LP: #1508706

 -- Kamal Mostafa <email address hidden> Fri, 20 Nov 2015 09:49:10 -0800

[Andris Petrams (andris-petrams)]

The computer is connected to two monitors to the motherboards DVI and VGA outputs.
When I installed Ubuntu version 16.04, i had a problem - after every computer restart VGA-monitor says "going to sleep" and darkens.
If I open "System Settings->Dysplays" and click on the monitor that is connected to the VGA,
"Switch Off->Apply->Keep Configuration" and then again "Switch On->Apply->Keep Configuration"
then both monitors are working normally, but after each restart i have to repeat these steps again.

The second option is - on the monitor settings, i set a small "Turn off inactive" time (1 minute)
and when the computer is switched on or restarted, I wait while the first monitor (DVI) is "going to sleep"
and then moving the mouse wakes up both. But if just turn on the computer and use it then VGA monitor never wakes up.

On two different computers with different motherboards MSI A75MA-P35 and the ASUS F1A75-V EVO,
but the same processors AMD A8-3870K with integrated Radeon graphics, the result is the same.

[Andris Petrams (andris-petrams)]

After last update problem solved on MSI A75MA-P35 but problem still persists on ASUS F1A75-V EVO

[Timo Aaltonen (tjaalton)]

this has nothing to do with radeon

[Andris Petrams (andris-petrams)]

I don't know with what it has to do, but I described the situation in a comment. So far, the problem affected both computers, but a few days ago the situation changed.

[Andris Petrams (andris-petrams)]

When I run following commands after logon then both monitors working properly
xrandr --output VGA-0 --off
xrandr --output VGA-0 --auto
xrandr --output VGA-0 --right-of DVI-0

[Andris Petrams (andris-petrams)]

Problem solved on Ubuntu 17.10 with gnome desktop