Still occurs on 5.4.0-31 update, only less severe. Laptop is useable now as long as no video is being played. By the looks of it, i915.enable_psr=0 as kernel boot parameter doesn't have any notable effect.
The logmessage using drm.debug=0x06 is as follows: [ 84.074499] [drm:drm_mode_addfb2 [drm]] [FB:192] [ 84.090664] [drm:drm_mode_addfb2 [drm]] [FB:220] [ 84.107575] [drm:drm_mode_addfb2 [drm]] [FB:192] [ 84.112742] [drm:i915_hotplug_work_func [i915]] running encoder hotplug functions [ 84.112772] [drm:i915_hotplug_work_func [i915]] Connector eDP-1 (pin 4) received hotplug event. [ 84.112802] [drm:intel_dp_detect [i915]] [CONNECTOR:191:eDP-1] [ 84.112831] [drm:intel_dp_print_rates [i915]] source rates: 162000, 216000, 270000, 324000, 432000, 540000 [ 84.112857] [drm:intel_dp_print_rates [i915]] sink rates: 162000, 216000, 243000, 270000, 324000, 378000, 432000, 540000 [ 84.112880] [drm:intel_dp_print_rates [i915]] common rates: 162000, 216000, 270000, 324000, 432000, 540000 [ 84.113411] [drm:intel_dp_get_dsc_sink_cap [i915]] DSC DPCD: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 84.113424] [drm:intel_dp_get_dsc_sink_cap [i915]] FEC CAPABILITY: 0 [ 84.113829] [drm:intel_dp_detect [i915]] MST support? port A: no, sink: no, modparam: yes [ 84.114226] [drm:drm_dp_get_edid_quirks [drm_kms_helper]] DP sink: EDID mfg 30-e4 prod-ID 1f-06 quirks: 0x0000 [ 84.125822] [drm:drm_mode_addfb2 [drm]] [FB:220] [ 84.142046] [drm:drm_mode_addfb2 [drm]] [FB:192] [ 84.160425] [drm:drm_mode_addfb2 [drm]] [FB:220] Instead of storms of hotplug events on 5.4.0-29, 5.4.0-31 has single hotplug events that cause a single flicker, instead of a storm of hotplug events. This makes the system almost useable. In 5.4.0-31 I noticed something else. Result of dmesg -w | grep vdd_edp dmesg -w | grep vdd [ 560.948837] [drm:edp_panel_vdd_on [i915]] Turning eDP port A VDD on [ 560.949091] [drm:edp_panel_vdd_on [i915]] PP_STATUS: 0x80000008 PP_CONTROL: 0x0000006f [ 567.912874] [drm:edp_panel_vdd_off_sync [i915]] Turning eDP port A VDD off [ 567.913095] [drm:edp_panel_vdd_off_sync [i915]] PP_STATUS: 0x80000008 PP_CONTROL: 0x00000067 [ 573.884411] [drm:edp_panel_vdd_on [i915]] Turning eDP port A VDD on [ 573.884594] [drm:edp_panel_vdd_on [i915]] PP_STATUS: 0x80000008 PP_CONTROL: 0x0000006f [ 580.969230] [drm:edp_panel_vdd_off_sync [i915]] Turning eDP port A VDD off [ 580.969377] [drm:edp_panel_vdd_off_sync [i915]] PP_STATUS: 0x80000008 PP_CONTROL: 0x00000067 [ 590.500251] [drm:edp_panel_vdd_on [i915]] Turning eDP port A VDD on [ 590.500480] [drm:edp_panel_vdd_on [i915]] PP_STATUS: 0x80000008 PP_CONTROL: 0x0000006f [ 594.537592] [drm:edp_panel_vdd_off_sync [i915]] Turning eDP port A VDD off It seems that the first that happens when watching a video or doing some more heavy graphics related stuff for some reason causes the edp panel to turn on, while it is already on and displaying video for some amounth of time. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1875649 Title: [Ice Lake] Screen flickering in Kubuntu 20.04 on Lenovo Yoga C940 14-IIL To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1875649/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
