Created attachment 114350 [details] dmesg ==System Environment== -------------------------- Regression: No. This is the first time to test this case on SKL. Non-working platforms: SKL Connecting monitors: eDP, DP(Dell UP32140Qt), HDMI ==kernel== -------------------------- -nightly: f7def439e21cacf7656539edc55a4884734743de (fails) ==Bug detailed description== ----------------------------- System output "ERROR" when it resumes from S4 with 3 pipe. ERROR: [drm:intel_dp_set_signal_levels] Using signal levels 07000000 [drm:intel_dp_set_signal_levels] Using signal levels 09000000 [drm:intel_dp_start_link_train [i915]] *ERROR* too many full retries, give up [drm:intel_dp_set_signal_levels] Using signal levels 09000000 [drm:intel_dp_set_signal_levels] Using signal levels 09000000 ==Reproduce steps== ---------------------------- 1. connect 3 monitor in total(eDP, DP, HDMI). 2. do S4
System will also output ERROR with only connecting DP monitor
(In reply to liulei from comment #1) > System will also output ERROR with only connecting DP monitor I mean: System output "ERROR" when it resumes from S4 with connecting DP monitor.
The cause should be because we didn't reinitialize the display and so the AUX transactions for the link training were failing. The driver has a lot more chances to work now (survived a few S4 cycles here).
Test it on the latest nightly kernel(790a30), this problem doest not exists. So verified.
Closing old verified.
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