Re: new monitor not going into power-saving mode
On 12/29/19 7:37 PM, Felix Miata wrote:
Gary Dale composed on 2019-12-29 18:33 (UTC-0500):
Is there something about DisplayPort that causes this behaviour or is it
specific to this monitor (Samsung LU28E490DS/ZA)?
I suspect the greatest likelihood is the Samsung, and least likely the DisplayPort
itself. My experience with DisplayPorts is that they are less likely to be trouble
than all other CRTCs combined.
Which DDX is X using? NVidia? AMDgpu? Nouveau? Intel? Modesetting? Radeon? Which
GPU and which Debian (IDs from inxi -GxxS)? Can you make a switch, e.g. from Intel
to Modesetting or vice versa?
I have an ASUS HD7850 card using the open-source drivers for AMD chipsets.
Do you have any power affecting settings in /etc/X11/xorg.con*?
No. Pretty much plain vanilla.
Things to try to narrow down or eliminate the fault:
Firmware upgrade for the Samsung.
None available.
Toggling the Samsung's eco saver.
No change.
Toggling the Samsung's MST setting if it has one.
Can't find one. Did find another setting about HB1 versus HB2 that I
changed without effect.
Another DisplayPort cable, even if you're using one that came with the display.
HDMI cable.
Didn't have another DP cable but the monitor also came with an HDMI
cable. Plugged that in and the screen energy saving mode kicks in fine.
I'll try some of your other suggestions below when I get the time. I'd
like to find out if this is an issue with the monitor, the display
adapter or the OS.
A virgin login user with Plasma.
A desktop or WM other than Plasma.
Emptying ~/.cache/ while logged out of X.
(as a test) reduce resolution, e.g. from 3840x2160 to 2560x1440.
A different PC.
A current mainline kernel version if not using Sid.
Live boot of some other distro, e.g. KDE Neon or Fedora 31/Plasma/KDE.
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