https://bugs.kde.org/show_bug.cgi?id=516479
--- Comment #4 from [email protected] --- This was still happening for me on Arch / Plasma 6.6.1 (my specs are in the duplicate bug https://bugs.kde.org/show_bug.cgi?id=516672). Note this was happening with the system being awake but the monitors powering down after inactivity/screenlock. Interestingly, it seems to have stopped happening after disabling MST on my displays' onboard menus (both older Dell UltraSharp LCD panels, both connected to the GPU via DisplayPort directly, no daisy-chaining so the MST enablement wasn't doing anything for me). I noted some oddities in dmesg when the displays were powered back on related to drm and amdgpu, as well as some powerdevil DDC messages in journalctl --user. Dmesg: 2221.315037] [drm] DM_MST: stopping TM on aconnector: 000000000b539075 [id: 104] [ 2222.129177] [drm] DM_MST: starting TM on aconnector: 000000000b539075 [id: 104] [ 2222.134729] [drm] DM_MST: DP12, 4-lane link detected [ 6800.207152] [drm] DM_MST: stopping TM on aconnector: 000000000b539075 [id: 104] [ 6801.029817] [drm] DM_MST: starting TM on aconnector: 000000000b539075 [id: 104] [ 6801.035371] [drm] DM_MST: DP12, 4-lane link detected [ 7007.899875] [drm] DM_MST: stopping TM on aconnector: 000000000b539075 [id: 104] [ 7008.110274] amdgpu 0000:03:00.0: [drm] REG_WAIT timeout 1us * 100 tries - dcn32_program_compbuf_size line:147 ================= PowerDevil: Feb 27 09:46:53 cezanne org_kde_powerdevil[19681]: [ 19734] Removing connected display on bus 11 Feb 27 09:46:53 cezanne org_kde_powerdevil[19681]: [ 19734] Emitting DDCA_Display_Status_Event[205.012: DDCA_EVENT_DISPLAY_DISCONNECTED, card1-DP-5, dref: DDCA_Display_Ref[2], io_path:/dev/i2c-11, ddc working: false] Feb 27 09:46:53 cezanne org_kde_powerdevil[19681]: [ 19734] Starting 1 callback threads Feb 27 09:46:53 cezanne org_kde_powerdevil[19681]: [ 19734] libddcutil callback thread 0x7f5774003e40 started Feb 27 09:46:53 cezanne org_kde_powerdevil[19681]: [ 19734] Started 1 event callback thread(s) Feb 27 09:46:53 cezanne org_kde_powerdevil[19681]: [ 20616] Invoking callback function 0x7f57a5d4b7f0 for event DDCA_Display_Status_Event[205.012: DDCA_EVENT_DISPLAY_DISCONNECTED, card1-DP-5, dref: DDCA_Display_Ref[2], io_path:/dev/i2c-11, ddc working: false] in this thread [ 20616] Feb 27 09:46:53 cezanne org_kde_powerdevil[19681]: [ 19734] Udev event detected Feb 27 09:46:53 cezanne org_kde_powerdevil[19681]: [ 20616] Callback function 0x7f57a5d4b7f0 for event DDCA_Display_Status_Event[205.012: DDCA_EVENT_DISPLAY_DISCONNECTED, card1-DP-5, dref: DDCA_Display_Ref[2], io_path:/dev/i2c-11, ddc working: false] complete Feb 27 09:46:53 cezanne org_kde_powerdevil[19681]: [ 19734] Udev event detected Feb 27 09:46:53 cezanne org_kde_powerdevil[19681]: [ 19734] Udev event detected Feb 27 09:46:53 cezanne org_kde_powerdevil[19681]: [ 19734] Udev event detected ================= Obviously whatever causes *that* isn't likely a Plasma issue, but from my naive understanding it appears to have the effect of hotplugging the display on wake (by hard-resetting the DP link). After disabling MST, the above messages haven't recurred and the times are synced across displays when they come up. So it looks like that DP reset on wake was tripping something up behind the scenes, at least on my machine? Hopefully the added context helps! -- You are receiving this mail because: You are watching all bug changes.
