Settings should be more cautious applying changes to display configuration. Changing resolution, etc., prompts with a 15 second timeout that backs everything out if the user didn't confirm (because they probably couldn't). What I ran into earlier today was switching "Color accuracy" from "efficiency" to "accuracy" (I know, serves me right), completely disabling my session because: kwin_core: Applying output config failed! kwin_wayland_drm: Atomic modeset commit failed! Invalid argument Which is probably an issue between GPU driver, GPU itself and the monitor, but backing out of was was not easy. It would be great of the settings offered an automatic backout on changing any options that modify the output configuration.
Hi - could you please help specify, is there a particular setting in that page that isn't offering the 15 second auto-revert? Or, are you requesting an additional revert mechanism that doesn't currently exist? Thanks!
(In reply to John Kizer from comment #1) > Hi - could you please help specify, is there a particular setting in that > page that isn't offering the 15 second auto-revert? Or, are you requesting > an additional revert mechanism that doesn't currently exist? > > Thanks! The one that screwed it up for me was the "Color accuracy". I think that any setting that would modify the output configuration (everything that goes into kwinoutputconfig.json) should trigger an auto back out timer. Not all options on this config page do.
Thanks - that's strange, I asked as I tried on my device, and changing the Color accuracy option actually did offer the 15-second timer! Could you provide specific steps that someone could follow to reproduce the issue of a revert timer not being offered, so we can narrow down the issue? See https://community.kde.org/Get_Involved/Issue_Reporting#Steps_to_Reproduce for an example. Thanks!
OK, this is not a kcm issue, but I would appreciate if you could help it categorize this properly. TLDR: changing this property for me does something that kwin can't recover from. KCM probably does offer to back out, but it can't when the time comes. I've tested this this way: $ kscreen-doctor output.DP-2.colorPowerTradeoff.preferAccuracy This sends the KWin session in a death spiral (for me). There is no video output. The picture appears frozen, but it's just showing whatever was last on the screens, switching to a text console and back then shows it frozen with what was last displayed on the text console. The logs are littered with this output: May 01 12:44:05 druid kwin_wayland[337695]: kwin_wayland_drm: Atomic modeset commit failed! Invalid argument May 01 12:44:05 druid kernel: HDR SB:3a 3d 47 40 09 01 03 00 09 01 09 01 00 00 00 00 May 01 12:44:05 druid kernel: HDR SB:01 1a 02 00 84 85 82 3b af 2f 79 8a 0a 1c df 0a May 01 12:44:05 druid kernel: HDR SB:3a 3d 47 40 09 01 03 00 09 01 09 01 00 00 00 00 May 01 12:44:05 druid kernel: HDR SB:01 1a 02 00 84 85 82 3b af 2f 79 8a 0a 1c df 0a May 01 12:44:05 druid kernel: HDR SB:3a 3d 47 40 09 01 03 00 09 01 09 01 00 00 00 00 May 01 12:44:05 druid kernel: HDR SB:01 1a 02 00 84 85 82 3b af 2f 79 8a 0a 1c df 0a May 01 12:44:05 druid kernel: HDR SB:3a 3d 47 40 09 01 03 00 09 01 09 01 00 00 00 00 May 01 12:44:05 druid kernel: HDR SB:01 1a 02 00 84 85 82 3b af 2f 79 8a 0a 1c df 0a May 01 12:44:05 druid kwin_wayland[337695]: kwin_core: Applying output config failed! Just repeating over and over, nothing else there that I can see. Attempting to "back out" doesn't work from kscreen-doctor: $ kscreen-doctor output.DP-2.colorPowerTradeoff.preferEfficiency applying config failed! The driver rejected the output configuration May 01 13:03:58 druid kwin_wayland[343847]: kwin_core: Applying output config failed! May 01 13:03:57 druid kwin_wayland[343847]: kwin_wayland_drm: drmModeListLessees() failed: Permission denied At this point, the only way to "fix" the situation (that I found) is to stop kwin, edit ~/.config/kwinoutputconfig.json to restore the value, and restart kwin. The "drmModeListLessees() failed: Permission denied" happens when I try to change the color accuracy to any value, bad or good, whether kwin runs or not, as long as kwin session is not on screen. I.e., it changes if I type it from a terminal in a kwin session, but fails with this error if I do it from a console terminal. This sounds to me that kscreen-doctor is asking kwin to apply the output changes, whether it's actually running the outputs or not, instead of asking it to apply the changes once it regains controls of the output. But that doesn't explain why kcm can't back out then, because I certainly waited for >15sec after making that change from kcm, and kept my vterm on kwin session during that time. OK, so I did this: from a terminal window in a kwin session: $ kscreen-doctor output.DP-2.colorPowerTradeoff.preferAccuracy ; sleep 5; kscreen-doctor output.DP-2.colorPowerTradeoff.preferEfficiency It still didn't recover (OK, so kcm would not be able to either): kscreen-doctor outpu: applying config failed! The driver rejected the output configuration logs: kwin_core: Applying output config failed! This time just that, no permission denied, no other messages whatsoever.
Thanks for the info! Based on the symptoms - log messages, 15 second revert not working, and what's displayed - this looks likely to be the same underlying issue as an existing bug report, so I'm merging these together for visibility and to help with coordinating diagnosing the issue. Thanks! *** This bug has been marked as a duplicate of bug 501094 ***