display/GFX issue with Ubuntu 16.04 not seen in 14.04

[Thomas Lübking]

On Tue, Aug 23, 2016 at 06:53:13AM -0400, Jim Abernathy wrote:
>
>
>On 08/19/2016 10:17 AM, Jim Abernathy wrote:
>>Not having much luck with the Distro forums on this issue so I 
>>thought I'd ask for advice here.
>>
>>I've been running Ubuntu 14.04.5 for some time on Intel Core i5 GFX 
>>without any issues.  My display is HDMI from the PC to an Onkyo A/V 
>>receiver then to a Sony KDL-XBR6.
>>
>>When I try a fresh install of 16.04.1, I get a display that blanks 
>>out for 3-5 seconds at random times depending on what is being 
>>displayed at the time.  I also have small abouts of video noise that 
>>is random horizontal lines about 1 pixel tall scattered through the 
>>page.
>>
>>I noticed that 14.04.05 uses X server 1.17.2 and 16.04.1 uses 1.18.3.
>>
>>When I do the command xrandr --verbose I see some small differences 
>>between 14.04 and 16.04, but it's things like 2 digits displayed 
>>instead of 1.  i.e. 60.0 vs. 60.00. I'm only concerned with 1080P 
>>HD.
>>
>>I've tried this on different computers all with Intel GFX. same results.
>>
>>This does not occur on other monitors or TVs.
>>
>>I'd blame it on Sony and Onkyo if they didn't work so well with 
>>Windows, all versions, and ubuntu all versions except 16.04.
>>
>>It's almost like the auto detection software in the newest version 
>>of X is off just enough to make my display flaky.  Kind of like the 
>>old analog CRT TVs that were sensitive to small tweaks to the 
>>horizontal and vertical adjustments.
>>
>>Any help would be appreciated.
>>
>>Jim A
>>
>
>Can someone let me know where I can ask questions regarding problems 
>with X??  I thought this forum would be the place?

Though this is very most likely a bug in the kernel and not in X11,
check whether you're using the intel (likely) or the modesetting driver,
then use the other one (uninstalling xf86-video-intel could be
sufficient for this, but I never used ubuntu. Ask them.)

Since it's also likely a bug in the kernel, check "dmesg | grep intel"
before doing so. You might face the same issue as this guy:
https://bbs.archlinux.org/viewtopic.php?id=216088

Cheers,
Thomas