Bug 206577

Summary:	Periodic screen blanking at a high refresh rate and resolution
Product:	Drivers	Reporter:	Tom Bazley (tombazley)
Component:	Video(DRI - non Intel)	Assignee:	drivers_video-dri
Status:	NEW ---
Severity:	normal	CC:	tombazley
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	5.5	Subsystem:
Regression:	No	Bisected commit-id:

Description Tom Bazley 2020-02-17 18:01:33 UTC

Using a Samsung LC43J892DKUXEN 43" monitor with a Vega 64. 

I am unable to set the display output to 3840x1200 @ 120Hz. At 100Hz the display behaves as expected, however at 120Hz the display will turn black briefly as if there is a power loss or as if the source input has changed. This will repeat maybe a couple of times every minute. 

I have tested using a ROG Strix RX VEGA64 OC edition and a Sapphire Radeon RX VEGA 64 Nitro+. 

I've tested on linux 5.5.2 and mesa 19.3.3, as well as on driver versions 19.9.3, 19.12.3, 19.7.5, 19.12.2, 20.1.1, and 20.2.1 on Windows. I submitted this issue to the AMD bug report a few weeks ago but haven't heard anything back from them, so I am submitting here as well. 

I had the monitor sent back to Samsung for testing. They used a STRIX GTX950 and had no issues. 

I have tried multiple DisplayPort cables including the one included with the monitor.