Eu tenho um Thinkpad X1C (gen 3) com o Arch Linux instalado. Quando eu conecto um monitor ao laptop DP, ele liga e desliga, algumas vezes causando pânico no kernel. Olhando para o log do sistema, vejo os seguintes erros em relação ao DP:
$ sudo journalctl -b 1 | grep drm | cut -d' ' -f 6- | sort | uniq
[drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
[drm:intel_dp_link_training_clock_recovery [i915]] *ERROR* failed to enable link training
[drm:intel_dp_link_training_clock_recovery [i915]] *ERROR* failed to get link status
[drm:intel_dp_link_training_clock_recovery [i915]] *ERROR* too many full retries, give up
[drm:intel_dp_start_link_train [i915]] *ERROR* failed to get link status
[drm:intel_dp_start_link_train [i915]] *ERROR* failed to start channel equalization
kernel: Linux 4.8.6-2-ck
xf86-video-intel: 1:2.99.917+725+gbf7316a-1
Tags intel-graphics thinkpad drm