Ubuntu
xserver-xorg-video-intel package

  1. Bug #1552040
  2. Comment #13

Comment 13 for bug 1552040

Revision history for this message
T (mightyowl) wrote : Re: Laptop sometimes doesn't detect external monitor

I have a Dell XPS 15 and connect over USB C to a display port hub to a HDMI external monitor.

Sometime in the past few months I ran into this issue. When I would lock my screen (xflock4) or go into standby the computer would lock up on resume and I had plenty of the following in the logs.

drm:intel_wait_ddi_buf_idle [i915_bpo]] *ERROR* Timeout waiting for DDI BUF B idle bit

It was fine on startup, as long as it didn't lock the screen.

I had been running kernel 4.4.0 on Xubuntu 16.04

I upgraded to kernel to 4.10.0 and my issue is now fixed.