Blurry image (LCD Overscan) on fresh install with kde plasma

ezequiel.ezb · 2021-06-02 18:11:14

Long story short I have a fucked up monitor (LG MG2280A).

On 1920x1080 it always has some scanning problem (typically underscan) on any OS. On Windows, however, once I install video drivers the GPU control panel has an option that fixes that, or alternatively I can edit the EDID profile using a specific program.

On Linux, Gnome 3 works just fine, Unity has a bit of underscan (black borders) but the image looks perfect, KDE has the right image size but it looks blurry.

I tried to take a picture with my cam but the image seems ok on the photo, so here is my xrandr output:

Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384
HDMI-A-0 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 476mm x 268mm
   1920x1080     59.93*+  60.00    60.00    60.00    50.00    50.00    59.94  
   1680x1050     59.88  
   1280x1024     60.02  
   1440x900      59.93  
   1280x960      60.00  
   1280x800      59.93  
   1280x720      60.00    50.00    59.94  
   1024x768      60.00  
   800x600       60.32  
   720x576       50.00  
   720x480       60.00    59.94  
   640x480       60.00    59.94  
   720x400       70.08  
DVI-D-0 disconnected (normal left inverted right x axis y axis)
DisplayPort-0 disconnected (normal left inverted right x axis y axis)

Last edited by ezequiel.ezb (2021-06-02 18:26:03)

Ropid · 2021-06-02 19:34:06

Your graphics card is Intel or AMD or Nvidia?

That program you are using in Windows is "CRU" = "Custom Resolution Utility"? If it's that CRU program, it can export an EDID binary file with your settings. You will be able to use that file in Linux. Are you using that CRU program? I can then try to help with how to use that exported EDID file in Linux with AMD graphics (and I think Intel).

You can see explanations about how using a custom EDID file works with AMD and Nvidia drivers in comments #7, #8, #9, #10, #11 of this kernel bug tracker entry here:

https://bugs.freedesktop.org/show_bug.cgi?id=110856

Last edited by Ropid (2021-06-02 19:35:57)

seth · 2021-06-02 20:08:53

"LG MG2280A" - google doesn't know the monitor (nor suggests an "you're too stupid to type a question and actually meant LG …" result)?
The pleathora of similar refresh rates look shady - you could try "--rate 50"

ezequiel.ezb · 2021-06-02 21:04:54

seth wrote:

"LG MG2280A" - google doesn't know the monitor (nor suggests an "you're too stupid to type a question and actually meant LG …" result)?
The pleathora of similar refresh rates look shady - you could try "--rate 50"

It's apparently not made by LG. It's (broken) default EDID profile and stuff like hwinfo (on linux) detect it as Goldstar Company Ltd M2280A.

This is a nightmare. I though just mine was broken but just today I found a complaint from about it here: https://forum.adrenaline.com.br/threads … em.648361/

The person attached two beautiful pictures of how the monitor's image looks by default:
https://uploaddeimagens.com.br/imagens/ … 145157-jpg

I was going to buy a new monitor but then someone gave me this and I spent the money with other hardware parts. Just later I found out the it's pure trash, anywhere you connect it shows these dreadful artifacts.

ezequiel.ezb · 2021-06-02 21:18:01

Ropid wrote:

Your graphics card is Intel or AMD or Nvidia?
That program you are using in Windows is "CRU" = "Custom Resolution Utility"? If it's that CRU program, it can export an EDID binary file with your settings. You will be able to use that file in Linux. Are you using that CRU program? I can then try to help with how to use that exported EDID file in Linux with AMD graphics (and I think Intel).
You can see explanations about how using a custom EDID file works with AMD and Nvidia drivers in comments #7, #8, #9, #10, #11 of this kernel bug tracker entry here:
https://bugs.freedesktop.org/show_bug.cgi?id=110856

My graphics is an integrated Vega 8 card. And yes, the program I was talking about is CRU. I will try this EDID exporting you mentioned but if I'm not mistaken I tried that before (on Kubuntu and on Manjaro KDE) and it didn't work.

But honestly, I'm losing hope.

I tried that trick where you calculate modelines using cvt, add a new mode with xrandr and then set it, but those commands have no effect at all, either in Arch or other distros.

The closest I got was this command, taken from the Arch Wiki's xrandr article:

xrandr --output HDMI-1 --mode 1920x1080 --rate 60

Images gets almost as sharp as in Windows/Gnome3 but overscan increases a lot.

I fixed the overscan with (also from the xrandr arch wiki page):

xrandr --output HDMI-0 --set underscan on --set "underscan vborder" 25 --set "underscan hborder" 40

But then the image got a little bit blurrier. I think I could use it like this, it looks good, but these configs are lost once I reboot, and the result sure could be better.

I'm checking this EDID thing again, thanks for the link.

Last edited by ezequiel.ezb (2021-06-02 21:22:02)

seth · 2021-06-02 21:37:23

https://toscode.gitee.com/linuxhw/EDID/ … C99C50F413 - no idea whether that yields better results.

xrandr --output HDMI-1 --mode 1920x1080 --rate 50

The from the edid freqs, I assume

% cvt12 1920 1080 60 -r
# 1920x1080 @ 60.000 Hz Reduced Blank (CVT) field rate 59.934 Hz; hsync: 66.587 kHz; pclk: 138.50 MHz
Modeline "1920x1080_60.00_rb1"  138.50  1920 1968 2000 2080  1080 1083 1088 1111 +hsync -vsync

or

cvt12 1920 1080 60 -b
# 1920x1080 @ 60.000 Hz Reduced Blank (CVT) field rate 60.000 Hz; hsync: 66.660 kHz; pclk: 133.32 MHz
Modeline "1920x1080_60.00_rb2"  133.32  1920 1928 1960 2000  1080 1097 1105 1111 +hsync -vsync

Should™ work…

ezequiel.ezb · 2021-06-02 22:01:43

seth wrote:

https://toscode.gitee.com/linuxhw/EDID/ … C99C50F413 - no idea whether that yields better results.

xrandr --output HDMI-1 --mode 1920x1080 --rate 50

The from the edid freqs, I assume

% cvt12 1920 1080 60 -r
# 1920x1080 @ 60.000 Hz Reduced Blank (CVT) field rate 59.934 Hz; hsync: 66.587 kHz; pclk: 138.50 MHz
Modeline "1920x1080_60.00_rb1"  138.50  1920 1968 2000 2080  1080 1083 1088 1111 +hsync -vsync

or

cvt12 1920 1080 60 -b
# 1920x1080 @ 60.000 Hz Reduced Blank (CVT) field rate 60.000 Hz; hsync: 66.660 kHz; pclk: 133.32 MHz
Modeline "1920x1080_60.00_rb2"  133.32  1920 1928 1960 2000  1080 1097 1105 1111 +hsync -vsync

Should™ work…

Ok bro (or sis, lol), I'm checking this within a minute. For now, I'm exploring some newfound knowledge gained here: https://www.monitortests.com/forum/Thre … 61#pid5761
Basically, the creator of the CRU utility giving some advice on how disabling extensions in the EDID profile fixes the overscan. I disabled my GPU's scaling settings and tried (on Windows) and restarted the driver, the overscan immediately went away, but the image turned gray-ish. I'll tinker a bit more to see if I can get rid of the overscan on Windows without using my gpu's control panel.

EDIT:

More newfound knowledge on how to fix this dreadful issue:
I just found out that this is not a regular monitor, but a TV/Monitor, so that explains the overscan (TVs tend to overscan HDMI signal by default).

That being said, you can disable it on the monitor itself: you have to go to access its Menu> 2nd Option (Picture) > 1st Option (Aspect Ratio) > Change from 16:9 too Just Scan

That fixed the overscan HOWEVER the image is just way too sharp now, fonts look like they'll pierce my eyes.

I'll check how this plays on Linux right now, it's better than nothing if it works, but on Windows I'm definitely not going to use this.

Last edited by ezequiel.ezb (2021-06-02 22:18:19)

ezequiel.ezb · 2021-06-02 22:38:36

seth wrote:

Should™ work…

The second option worked perfectly (rb2) AFTER setting refresh rate to 50hz. Config was not retained after reboot though.

Btw, do you have any idea on how I could set this on Windows? I just checked the hex code in this link you provided, it matches perfectly the default EDID file in my monitor.

Could you elaborate on the second modelines you posted and how you figured it out? Any idea on how to possibly bring that to windows? If it's of any help, when I disable CTA-861 extensions on Windows, resolution/scan stays perfect, but colors become dull and grayish.

Btw thanks, you're the first one to ever figure out how to get this working with linux.

Last edited by ezequiel.ezb (2021-06-03 02:41:22)

seth · 2021-06-03 05:46:52

The EDID I linked has

Monitor ranges (GTF): 48-61Hz V, 28-83kHz H, max dotclock 150MHz

- the regular pclk is

% cvt12 1920 1080 60
# 1920x1080 @ 60.000 Hz (CVT) field rate 59.963 Hz; hsync: 67.158 kHz; pclk: 173.00 MHz
Modeline "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync

ie. "too much" and the modelines in the edid are all very low, so I figured we just hammer that down as much as possible (which is always a good idea with distorted outputs)

You can add the modes to the server https://wiki.archlinux.org/title/Xrandr … esolutions
The PreferredMode is likely useless because the userspace/session will "restore" its own resolution.
You might have resort to some https://wiki.archlinux.org/title/XDG_Autostart or a server setup script (depends on how you start the session)

I don't see why or think that you need to first switch to 50Hz here.

The blurriness is btw. likely because the edid announces some interlaced modes, you could check "xrandr --verbose" to see which is selected as default.

As for windows, I guess the CRU author can explain how to add a custom modeline this way?

ezequiel.ezb · 2021-06-03 12:45:03

seth wrote:

The EDID I linked has
Monitor ranges (GTF): 48-61Hz V, 28-83kHz H, max dotclock 150MHz
- the regular pclk is
% cvt12 1920 1080 60
# 1920x1080 @ 60.000 Hz (CVT) field rate 59.963 Hz; hsync: 67.158 kHz; pclk: 173.00 MHz
Modeline "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync
ie. "too much" and the modelines in the edid are all very low, so I figured we just hammer that down as much as possible (which is always a good idea with distorted outputs)
You can add the modes to the server https://wiki.archlinux.org/title/Xrandr … esolutions
The PreferredMode is likely useless because the userspace/session will "restore" its own resolution.
You might have resort to some https://wiki.archlinux.org/title/XDG_Autostart or a server setup script (depends on how you start the session)
I don't see why or think that you need to first switch to 50Hz here.
The blurriness is btw. likely because the edid announces some interlaced modes, you could check "xrandr --verbose" to see which is selected as default.
As for windows, I guess the CRU author can explain how to add a custom modeline this way?

Oh, I see. Yesterday I executed the "xrandr --output HDMI-1 --mode 1920x1080 --rate 50" command you mentioned along with setting the modelines and thought the result was good, but I may have messed up.
Today I walked through the whole process again.

1. Booted the PC, previous xrandr config was lost, image looks blurry
2. xrandr --verbose
It produces a lot of output, but the relevant part is:

xrandr --verbose
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384
HDMI-A-0 connected primary 1920x1080+0+0 (0x6ea) normal (normal left inverted right x axis y axis) 476mm x 268mm
        Identifier: 0x53
        Timestamp:  1567980
        Subpixel:   unknown
        Gamma:      1.0:1.0:1.0
        Brightness: 1.0
        Clones:    
        CRTC:       0
        CRTCs:      0 1 2 3
        Transform:  1.000000 0.000000 0.000000
                    0.000000 1.000000 0.000000
                    0.000000 0.000000 1.000000
                   filter: 
        EDID: 
                00ffffffffffff001e6dec5701010101
                0114010380301b78ea9535a159579f27
                0e5054a10800b3008180714081400101
                0101010101011a3680a070381f403020
                3500dc0c1100001a023a801871382d40
                532c4500dc0c1100001e000000fd0030
                3d1c530f000a202020202020000000fc
                004d32323830410a20202020202001dd
                020319f14a900403011412051f101323
                09070765030c001000023a801871382d
                40582c4500dc0c1100001a011d801871
                1c1620582c2500dc0c1100009e011d00
                7251d01e206e285500dc0c1100001e01
                1d80d0721c1620102c2580c48e210000
                9e023a80d072382d40102c4520064421
                00001e00000000000000000000000083

The EDID data matches the one from my backup and from the link you posted.

And:

  1920x1080 (0x5c) 148.500MHz +HSync +VSync *current
        h: width  1920 start 2448 end 2492 total 2640 skew    0 clock  56.25KHz
        v: height 1080 start 1084 end 1089 total 1125           clock  50.00Hz

Image looks extremely blurry but fits the screen.
After that i ran:

xrandr --newmode   "1920x1080_60.00_rb2"  133.32  1920 1928 1960 2000  1080 1097 1105 1111 +hsync -vsync
xrandr --addmode HDMI-A-0 1920x1080_60.00_rb2
xrandr --output HDMI-A-0 1920x1080_60.00_rb2 
xrandr --output HDMI-A-0 1920x1080_60.00_rb2

The screen flashed, new resolution is set, as xrandr --verbose now shows

  1920x1080_60.00_rb2 (0x6ea) 133.320MHz +HSync -VSync *current
        h: width  1920 start 1928 end 1960 total 2000 skew    0 clock  66.66KHz
        v: height 1080 start 1097 end 1105 total 1111           clock  60.00Hz

However, the image looks exactly the same as before, blurry, no overscan.

If I run the "xrandr --output HDMI-1 --mode 1920x1080 --rate 50" command, the image looks good, but it has considerable overscan.
The thing is, when I set the monitor to use "just scan" and the image looks good, it shows me the resolution is at "1080p@50hz", that shows up automatically on the OSD.
So I'm really starting to thing this monitor is supposed to work in 50hz, not 60.

For now, I'll be using it with this "Just Scan" settings despite the sharpness issue, I think you should not bother anymore, you did enough, thanks.

Last edited by ezequiel.ezb (2021-06-03 13:18:45)

Arch Linux

#1 2021-06-02 18:11:14

Blurry image (LCD Overscan) on fresh install with kde plasma

#2 2021-06-02 19:34:06

Re: Blurry image (LCD Overscan) on fresh install with kde plasma

#3 2021-06-02 20:08:53

Re: Blurry image (LCD Overscan) on fresh install with kde plasma

#4 2021-06-02 21:04:54

Re: Blurry image (LCD Overscan) on fresh install with kde plasma

#5 2021-06-02 21:18:01

Re: Blurry image (LCD Overscan) on fresh install with kde plasma

#6 2021-06-02 21:37:23

Re: Blurry image (LCD Overscan) on fresh install with kde plasma

#7 2021-06-02 22:01:43

Re: Blurry image (LCD Overscan) on fresh install with kde plasma

#8 2021-06-02 22:38:36

Re: Blurry image (LCD Overscan) on fresh install with kde plasma

#9 2021-06-03 05:46:52

Re: Blurry image (LCD Overscan) on fresh install with kde plasma

#10 2021-06-03 12:45:03

Re: Blurry image (LCD Overscan) on fresh install with kde plasma

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