Night light still turned on on one monitor after resume
It appears that some users have issues that night light is still turned on even though it is daytime.
One corner cases where this may happen (there may be more):
- Night light is on and no monitor is attached
- User suspends
- sunrise happens
- User attaches a new monitor
- User resumes the machine
In this case, the new monitor may have night light applied. What appears to happen is that CRTC 0 (from the internal monitor) is reassigned to the external monitor. However, for some reason the CRTC 0 ends up with the modified gamma curve again.
An explanation may be a race condition where various gamma curve updates are applied in the wrong order.
Note that the patch from https://bugzilla.gnome.org/show_bug.cgi?id=786569 appears to make this event less likely.