I want to check if eDP will reset and flicker the LVDS while we launch the monitor setting tool on UBUntu, because the LVDS will not flicker on Windows O.S while we set dual monitor. I press “Display Settings” on 45 seconds at dmesg log with drm debug. Platform: Haswell Core-i5-4300 O.S LUBuntu 16.04 x64 Kernel 4.15.0 [ 17.570368] wlp4s0: associated [ 17.606437] IPv6: ADDRCONF(NETDEV_CHANGE): wlp4s0: link becomes ready [ 45.120936] [drm:drm_helper_probe_single_connector_modes [drm_kms_helper]] [CONNECTOR:59:eDP-1] [ 45.120977] [drm:intel_dp_detect [i915]] [CONNECTOR:59:eDP-1] [ 45.121008] [drm:intel_dp_print_rates [i915]] source rates: 162000, 270000, 540000 [ 45.121034] [drm:intel_dp_print_rates [i915]] sink rates: 162000, 270000 [ 45.121059] [drm:intel_dp_print_rates [i915]] common rates: 162000, 270000 [ 45.121085] [drm:edp_panel_vdd_on [i915]] Turning eDP port A VDD on [ 45.121114] [drm:edp_panel_vdd_on [i915]] PP_STATUS: 0x80000008 PP_CONTROL: 0x0000000f [ 45.121611] [drm:drm_dp_read_desc [drm_kms_helper]] DP sink: OUI 2b-02-f0 dev-ID CH7511 HW-rev 1.0 SW-rev 1.0 quirks 0x0000 [ 45.122045] [drm:intel_dp_check_link_status [i915]] DDI A: channel EQ not ok, retraining [ 45.123021] [drm:intel_dp_set_signal_levels [i915]] Using signal levels 00000000 [ 45.123037] [drm:intel_dp_set_signal_levels [i915]] Using vswing level 0 [ 45.123052] [drm:intel_dp_set_signal_levels [i915]] Using pre-emphasis level 0 [ 45.123068] [drm:intel_dp_program_link_training_pattern [i915]] Using DP training pattern TPS1 [ 45.123804] [drm:intel_dp_set_signal_levels [i915]] Using signal levels 04000000 [ 45.123829] [drm:intel_dp_set_signal_levels [i915]] Using vswing level 1 [ 45.123851] [drm:intel_dp_set_signal_levels [i915]] Using pre-emphasis level 0 [ 45.124568] [drm:intel_dp_start_link_train [i915]] clock recovery OK [ 45.124586] [drm:intel_dp_program_link_training_pattern [i915]] Using DP training pattern TPS2 [ 45.125605] [drm:intel_dp_set_signal_levels [i915]] Using signal levels 05000000 [ 45.125621] [drm:intel_dp_set_signal_levels [i915]] Using vswing level 1 [ 45.125636] [drm:intel_dp_set_signal_levels [i915]] Using pre-emphasis level 1 [ 45.126631] [drm:intel_dp_set_signal_levels [i915]] Using signal levels 06000000 [ 45.126647] [drm:intel_dp_set_signal_levels [i915]] Using vswing level 1 [ 45.126664] [drm:intel_dp_set_signal_levels [i915]] Using pre-emphasis level 2 [ 45.127660] [drm:intel_dp_start_link_train [i915]] Channel EQ done. DP Training successful [ 45.127684] [drm:intel_dp_start_link_train [i915]] [CONNECTOR:59:eDP-1] Link Training Passed at Link Rate = 270000, Lane count = 2 [ 45.135918] [drm:drm_add_display_info [drm]] non_desktop set to 0 [ 45.135935] [drm:drm_add_edid_modes [drm]] ELD: no CEA Extension found [ 45.135946] [drm:drm_add_display_info [drm]] non_desktop set to 0 [ 45.135974] [drm:drm_helper_probe_single_connector_modes [drm_kms_helper]] [CONNECTOR:59:eDP-1] probed modes : [ 45.135988] [drm:drm_mode_debug_printmodeline [drm]] Modeline 60:"1366x768" 60 72250 1366 1414 1446 1526 768 771 781 791 0x48 0x9 [ 45.136404] [drm:drm_helper_probe_single_connector_modes [drm_kms_helper]] [CONNECTOR:66:HDMI-A-1] [ 45.136446] [drm:intel_hdmi_detect [i915]] [CONNECTOR:66:HDMI-A-1] [ 45.136644] [drm:gmbus_xfer [i915]] GMBUS [i915 gmbus dpb] NAK for addr: 0050 w(1) [ 45.136672] [drm:gmbus_xfer [i915]] GMBUS [i915 gmbus dpb] NAK on first message, retry [ 45.136865] [drm:gmbus_xfer [i915]] GMBUS [i915 gmbus dpb] NAK for addr: 0050 w(1) [ 45.136879] [drm:drm_do_probe_ddc_edid [drm]] drm: skipping non-existent adapter i915 gmbus dpb [ 45.136904] [drm:intel_hdmi_set_edid [i915]] HDMI GMBUS EDID read failed, retry using GPIO bit-banging [ 45.136928] [drm:intel_gmbus_force_bit [i915]] enabling bit-banging on i915 gmbus dpb. force bit now 1 [ 45.137604] [drm:drm_do_probe_ddc_edid [drm]] drm: skipping non-existent adapter i915 gmbus dpb [ 45.137629] [drm:intel_gmbus_force_bit [i915]] disabling bit-banging on i915 gmbus dpb. force bit now 0 [ 45.137807] [drm:gmbus_xfer [i915]] GMBUS [i915 gmbus dpb] NAK for addr: 0040 w(1) [ 45.137825] [drm:gmbus_xfer [i915]] GMBUS [i915 gmbus dpb] NAK on first message, retry [ 45.138000] [drm:gmbus_xfer [i915]] GMBUS [i915 gmbus dpb] NAK for addr: 0040 w(1) [ 45.138006] [drm:drm_dp_dual_mode_detect [drm_kms_helper]] DP dual mode HDMI ID: (err -6) [ 45.138011] [drm:drm_helper_probe_single_connector_modes [drm_kms_helper]] [CONNECTOR:66:HDMI-A-1] disconnected [ 47.512164] random: crng init done [ 48.361524] [drm:edp_panel_vdd_off_sync [i915]] Turning eDP port A VDD off [ 48.361562] [drm:edp_panel_vdd_off_sync [i915]] PP_STATUS: 0x80000008 PP_CONTROL: 0x00000007
Reporter, can you please attach the full dmesg log from boot with kernel parameters drm.debug=0x1e log_buf_len=4M. How often you see the flicker? Every time when display settings are opened? Have you tried with latest kernel? https://cgit.freedesktop.org/drm-tip)
Created attachment 142611 [details] dmesg with drm.debug=0x1e Yes, every time when display settings are opened.
Can you reproduce with latest kernel? 4.20 is the latest kernel today, 4.16 is old. Logs from latest kernel will help in Investigation/Debugging.
Created attachment 142612 [details] dmesg with drm.debug=0x1e kernel 4.20.rc4 The 4.20.RC4 kernel does not have the flicker issue, please find the log in the attached.
I'm inclined to close this bug as already fixed as it works on the recent kernels. Even if we can't say what exactly the fix was. A reverse bisect might be useful in identifying which commit fixed the issue; however v4.16 is no longer supported and will not receive stable kernel updates anymore.
Hi, stable kernel 4.19.4 is also work and does not have flicker issue, many thanks.
Considering no issues with latest kernel (4.19/4.20), closing this bug.
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