I see the same FIFO under-run issue in Kubuntu 16.04. The manifestation appears to be either the laptop display remaining totally blank (but not disabled - the pointer appears to travel through it) on boot-up, resume from lid-open or resume from screensaver, or the display going blank when the mouse pointer enters the laptop screen and resuming when the pointer exits - but always in the presence of a second display connected over HDMI. Temporary "fixes" have so far included closing the lid and opening (often seems to resolve the blank state from screensaver) and unplugging and re-plugging HDMI, which sometimes sorts the blanking on mouse pointer problem.
sample errors: [ 90.483130] [drm:intel_cpu_fifo_underrun_irq_handler [i915_bpo]] *ERROR* CPU pipe A FIFO underrun [ 139.548826] [drm:intel_cpu_fifo_underrun_irq_handler [i915_bpo]] *ERROR* CPU pipe A FIFO underrun -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1568865 Title: [drm:intel_cpu_fifo_underrun_irq_handler [i915_bpo]] *ERROR* CPU pipe B FIFO underrun To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1568865/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
