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Is there anyone that is familiar with the i915 video driver issues with 16.04? For me, it manifests as the external monitors going blank intermittently and then combing back on after a few seconds. I've attempted the fix at https://aboutsimon.com/blog/2016/07/...ntel-i915.html which did not correct the issue.

I have attempted to install kernel 4.6, but it only resulted in a blank screen immediately after the login screen was displayed upon boot-up.

The output of lshw -c video is as follows:

*-display 
description: VGA compatible controller
product: Broadwell-U Integrated Graphics
vendor: Intel Corporation
physical id: 2
bus info: pci@0000:00:02.0
version: 09
width: 64 bits
clock: 33MHz
capabilities: msi pm vga_controller bus_master cap_list rom
configuration: driver=i915 latency=0
resources: irq:48 memory:f6000000-f6ffffff memory:e0000000-efffffff ioport:f000(size=64)

Current kernel information is as follows:

simpsonc@simpsonc-nbk:~$ uname -r
4.4.0-36-generic

simpsonc@simpsonc-nbk:~$ uname -v
#55-Ubuntu SMP Thu Aug 11 18:01:55 UTC 2016

When an external monitor goes blank, the following errors are sometimes written to syslog:

Sep 4 16:49:00 simpsonc-nbk kernel: [ 9709.832348] [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
Sep 4 17:13:48 simpsonc-nbk kernel: [11197.640834] [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe C FIFO underrun

It may also be worth noting that this seems to coincide with keystrokes, but this may be merely a coincidence. Any assistance or advice would be greatly appreciated as this has become quite annoying. Please let me know if any further information would be helpful.

edwinksl
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gajuith
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  • Same issue here, but my laptop runs 4.7.2. I also did update recently from 15.04 to .10, to 16.04.1 — it's all the same pain: unity doesn't resume its operations after suspend. I suspect it's related to its Composite use, since other WMs w/o fancy graphics doesn't suffer from that. – poige Sep 11 '16 at 15:17

1 Answers1

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Try plugging in headphones per https://github.com/rolandguelle/razer-blade-stealth-linux/issues/18. This seems to have fixed it for me for the time being on a Dell Precision 5520 linked to 2 external monitors via TB16/DP.

@brendanrankin says: "A bit of an odd thing happened just now. I discovered that if I have a headset plugged in the issue goes away. The same thing applies if I choose anything other than "built in audio" as the output channel. I have two audio capable monitors that I combine to operate as left and right channels....no video glitches when I use those or headphones plugged into the laptop. As soon as I unplug the headphones and the laptop reverts to its own speakers, the monitor connected to the HDMI port starts "glitching".

I'm not sure what value this post brings anyone, but (for me) it makes my RBS much more tolerable to use when "docked". :-) ...

Funky issue, but since HDMI (and DP) standards support audio and video over the same wires it "feels" like an audio/video channelization issue. I'll work to file this at freedesktop.org and/or see if it's already been filed."

Jason
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