Bug 99368

Summary: Full aspect scaling introduces interlacing on specific resolutions
Product: DRI Reporter: Platin <gamwizh00>
Component: DRM/RadeonAssignee: Default DRI bug account <dri-devel>
Status: RESOLVED MOVED QA Contact:
Severity: normal    
Priority: medium CC: abolte
Version: unspecified   
Hardware: x86-64 (AMD64)   
OS: Linux (All)   
i915 platform: i915 features:
Description Flags
dmesg log
Xorg log
xrandr --verbose
Image showing interlacing
Correct Xorg log none

Description Platin 2017-01-11 21:47:34 UTC
Created attachment 128897 [details]
dmesg log

When using full aspect scaling in xrandr on a laptop with an A6-6310 apu the display is showing interlaced lines across the whole display.

This happens only on some of the supported resolutions of the integrated display, those being 1280x720 and 1152x768.
Comment 1 Platin 2017-01-11 21:48:00 UTC
Created attachment 128898 [details]
Xorg log
Comment 2 Platin 2017-01-11 21:48:34 UTC
Created attachment 128899 [details]
xrandr --verbose
Comment 3 Platin 2017-01-11 22:27:35 UTC
Created attachment 128901 [details]
Image showing interlacing
Comment 4 Platin 2017-01-11 22:29:35 UTC
The interlacing is not visible on screenshots
Comment 5 Platin 2017-01-30 13:01:27 UTC
Created attachment 129229 [details]
Correct Xorg log

Didn't know that GDM doesn't store the Xorg log in the usual location. So I accidentally uploaded an obsolete log. Replaced it with the correct log.

I tried lower resolutions with the amdgpu driver and the problem shows even there. So I'm not sure if the problem exists on both drivers or if the source of the problem lies elsewhere.

Does anyone have an idea?
Comment 6 Adam Bolte 2017-04-21 12:47:15 UTC
I'm seeing this too. Running a BenQ XL2730Z (2560x1440@144Hz) gaming monitor, but some games (eg. Prototype 2 under Wine, Saints Row 2) only accept resolutions up to 1920x1080. They cause GPU scaling to automatically kick in (the monitor reports the resolution is still 2560x1440) and everything looks too horrible to look at.

Fury X, Mesa 17.0.1.

If I run the scaling mode with Center instead of Full aspect, everything looks great (but annoyingly small).
Comment 7 Platin 2018-05-27 00:01:06 UTC
The issue is fixed on the mainline kernel 4.17.0-rc6 using the amdgpu drm driver. This was recently fixed it seems since the issue persists on 4.16.11.

It is required to force enable DC though. Without it, it won't work.
Comment 8 Martin Peres 2019-11-19 09:23:15 UTC
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