<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [SKL] Flashing black screen with dual monitors" href="https://bugs.freedesktop.org/show_bug.cgi?id=99322#c3">Comment # 3</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [SKL] Flashing black screen with dual monitors" href="https://bugs.freedesktop.org/show_bug.cgi?id=99322">bug 99322</a> from <a class="email" href="mailto:tim@buttersideup.com" title="Tim Small <tim@buttersideup.com>"> Tim Small</a> <pre>Just running with the other monitor for the time being (Dell switched off, AOC U2879VF switched on). The AOC just went blank three times, for about 2 seconds at a time, with about 2 seconds between each blank. This occurred about 1.5 minutes after the following kernel messages. Nothing happened which should have caused a hotplug event AFAIK, and I didn't notice any display disturbance at 09:27:35. Jan 9 09:27:35 ermintrude kernel: [144836.324366] [drm:intel_get_hpd_pins [i915]] hotplug event received, stat 0x00400000, dig 0x10101110, pins 0x00000040 Jan 9 09:27:35 ermintrude kernel: [144836.324380] [drm:intel_hpd_irq_handler [i915]] digital hpd port C - short Jan 9 09:27:35 ermintrude kernel: [144836.324398] [drm:intel_dp_hpd_pulse [i915]] got hpd irq on port C - short Jan 9 09:27:35 ermintrude kernel: [144836.324796] [drm:intel_dp_read_dpcd [i915]] DPCD: 12 14 c4 01 01 00 01 00 02 02 06 00 00 00 00 Jan 9 09:27:35 ermintrude kernel: [144836.325619] [drm:intel_dp_check_link_status [i915]] DDI C: channel EQ not ok, retraining Jan 9 09:27:35 ermintrude kernel: [144836.326502] [drm:intel_dp_set_signal_levels [i915]] Using signal levels 00000000 Jan 9 09:27:35 ermintrude kernel: [144836.326512] [drm:intel_dp_set_signal_levels [i915]] Using vswing level 0 Jan 9 09:27:35 ermintrude kernel: [144836.326521] [drm:intel_dp_set_signal_levels [i915]] Using pre-emphasis level 0 Jan 9 09:27:35 ermintrude kernel: [144836.326531] [drm:intel_dp_program_link_training_pattern [i915]] Using DP training pattern TPS1 Jan 9 09:27:35 ermintrude kernel: [144836.327099] [drm:intel_dp_set_signal_levels [i915]] Using signal levels 04000000 Jan 9 09:27:35 ermintrude kernel: [144836.327109] [drm:intel_dp_set_signal_levels [i915]] Using vswing level 1 Jan 9 09:27:35 ermintrude kernel: [144836.327118] [drm:intel_dp_set_signal_levels [i915]] Using pre-emphasis level 0 Jan 9 09:27:35 ermintrude kernel: [144836.327678] [drm:intel_dp_set_signal_levels [i915]] Using signal levels 07000000 Jan 9 09:27:35 ermintrude kernel: [144836.327687] [drm:intel_dp_set_signal_levels [i915]] Using vswing level 2 Jan 9 09:27:35 ermintrude kernel: [144836.327696] [drm:intel_dp_set_signal_levels [i915]] Using pre-emphasis level 0 Jan 9 09:27:35 ermintrude kernel: [144836.328257] [drm:intel_dp_start_link_train [i915]] clock recovery OK Jan 9 09:27:35 ermintrude kernel: [144836.328266] [drm:intel_dp_program_link_training_pattern [i915]] Using DP training pattern TPS3 Jan 9 09:27:35 ermintrude kernel: [144836.329133] [drm:intel_dp_set_signal_levels [i915]] Using signal levels 08000000 Jan 9 09:27:35 ermintrude kernel: [144836.329142] [drm:intel_dp_set_signal_levels [i915]] Using vswing level 2 Jan 9 09:27:35 ermintrude kernel: [144836.329151] [drm:intel_dp_set_signal_levels [i915]] Using pre-emphasis level 1 Jan 9 09:27:35 ermintrude kernel: [144836.330007] [drm:intel_dp_set_signal_levels [i915]] Using signal levels 08000000 Jan 9 09:27:35 ermintrude kernel: [144836.330016] [drm:intel_dp_set_signal_levels [i915]] Using vswing level 2 Jan 9 09:27:35 ermintrude kernel: [144836.330025] [drm:intel_dp_set_signal_levels [i915]] Using pre-emphasis level 1 Jan 9 09:27:35 ermintrude kernel: [144836.330882] [drm:intel_dp_start_link_train [i915]] Channel EQ done. DP Training successful Jan 9 09:27:35 ermintrude kernel: [144836.355682] [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are on the CC list for the bug.</li> <li>You are the assignee for the bug.</li> </ul> </body> </html>