Monitors immediately come out of energy saving mode

[amichair]

On Kubuntu 16.04 with kernel 4.4.0-22.39-generic 4.4.8, but it's been like this since 15.10 a few kernels back. Multiple screens connected. Intel i7 4771 Haswell with only integrated GPU (no dedicated graphics card).

What happens is that the monitors do enter energy saving mode at the configured timeout of user inactivity, but a couple seconds later they snap right out of it. Usually when I come back to my computer after being away there are also a few Plasma crash dialogs. My monitors haven't been saving energy (or pixel life) in over half a year now.

The only evidence I found in the system log, which I'm not sure is related but might be worth mentioning, is:

[Mon May 9 00:29:03 2016] snd_hda_codec_hdmi hdaudioC0D0: HDMI: ELD buf size is 0, force 128
[Mon May 9 00:29:03 2016] snd_hda_codec_hdmi hdaudioC0D0: HDMI: invalid ELD data byte 0

[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 1579579

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.

[amichair (amichai2)]

$ apport-collect 1579579
ERROR: Could not import module, is a package upgrade in progress? Error: No module named PyQt5.QtCore

[Joseph Salisbury (jsalisbury)]

Did this issue start happening after an update/upgrade? Was there a prior kernel version where you were not having this particular problem?

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.6 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.6-rc7-wily/

[penalvch (penalvch)]

amichair, in addition to https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1579579/comments/3 , instead of the graphical apport-collect, could you please try the below:
apport-cli -u 1579579

[amichair (amichai2)]

$ apport-cli -u 1579579
ERROR: You need to use apport-collect for updating an existing bug

[penalvch (penalvch)]

amichair, one may use a non-KDE environment such as http://cdimage.ubuntu.com/daily-live/current/ to run apport-collect in a live environment.

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]

[amichair (amichai2)]

I changed my monitor input source selection from Auto to HDMI (which is the only used connector), and this no longer happens. Since I have a workaround, you can close the issue. If someone else will encounter this issue, I can recreate it and try to provide the missing info (which currently requires some work to do, so is not worth it).