few tests - dmesg-warn/dmesg-fail - Link Training Unsuccessful
<7> [431.843812] xe 0000:03:00.0: [drm:intel_dp_get_adjust_train [xe]] [CONNECTOR:264:DP-3][ENCODER:263:DDI C/PHY C][DPRX] 8b/10b, lanes: 1, vswing request: 1/0/0/0, pre-emphasis request: 0/0/0/0
<7> [431.843940] xe 0000:03:00.0: [drm:intel_dp_set_signal_levels [xe]] [CONNECTOR:264:DP-3][ENCODER:263:DDI C/PHY C][DPRX] 8b/10b, lanes: 1, vswing levels: 1/1/1/1, pre-emphasis levels: 0/0/0/0
<7> [431.844447] xe 0000:03:00.0: [drm:intel_dp_dump_link_status [xe]] [CONNECTOR:264:DP-3][ENCODER:263:DDI C/PHY C][DPRX] ln0_1:0x1 ln2_3:0x0 align:0x0 sink:0x3 adj_req0_1:0x1 adj_req2_3:0x0
<7> [431.844552] xe 0000:03:00.0: [drm:intel_dp_link_train_phy [xe]] [CONNECTOR:264:DP-3][ENCODER:263:DDI C/PHY C][DPRX] Channel equalization failed 5 times
<7> [431.844653] xe 0000:03:00.0: [drm:intel_dp_link_train_phy [xe]] [CONNECTOR:264:DP-3][ENCODER:263:DDI C/PHY C][DPRX] Link Training failed at link rate = 162000, lane count = 1
<3> [431.845095] xe 0000:03:00.0: [drm] *ERROR* Link Training Unsuccessful
<7> [431.846019] xe 0000:03:00.0: [drm:intel_get_hpd_pins [xe]] hotplug event received, stat 0x00040000, dig 0x00008988, pins 0x00000040, long 0x00000000
<7> [431.846122] xe 0000:03:00.0: [drm:intel_hpd_irq_handler [xe]] digital hpd on [ENCODER:263:DDI C/PHY C] - short
<7> [431.846260] xe 0000:03:00.0: [drm:intel_dp_hpd_pulse [xe]] got hpd irq on [ENCODER:263:DDI C/PHY C] - short
<7> [431.848913] xe 0000:03:00.0: [drm:drm_dp_read_dpcd_caps [drm_display_helper]] AUX C/DDI C/PHY C: Base DPCD: 12 14 c4 81 01 00 01 c1 02 02 06 00 00 00 80
<7> [431.848932] xe 0000:03:00.0: [drm:drm_dp_read_dpcd_caps [drm_display_helper]] AUX C/DDI C/PHY C: DPCD: 14 1e c4 81 01 00 01 c1 02 02 06 00 00 00 81