Arch Linux

m73

Member

Registered: 2012-06-04

Posts: 13

[SOLVED] Xrandr mode stopped working after update

Hey. I just finished updating my system after a few months after the last one, and now my xrandr sequence doesn't work anymore to tweak my external monitor:

xrandr --newmode "1920x1080_60.00"  173.00  1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync
xrandr --addmode DP2-3 "1920x1080_60.00"
xrandr --output DP2-3 --mode "1920x1080_60.00"

What I get is:

xrandr: Configure crtc 1 failed

...which is due to the last command. The screen flickers a bit and then it goes back to the previous mode. I tried lowering the resolution, getting the new line with cvt, but then I get a "fuzzy" screen with a part of the bottom cut off.

I'm using Awesome WM and connect to the screen via VGA cable.

This used to work just fine, so is anyone aware of what could've changed and how to fix this? Thanks.

Last edited by m73 (2020-04-23 21:52:05)

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 77,699

Re: [SOLVED] Xrandr mode stopped working after update

Does either of those work?

# 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
# 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

Why do you have to add the rate itfp?

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m73

Member

Registered: 2012-06-04

Posts: 13

Re: [SOLVED] Xrandr mode stopped working after update

Sweet. Yea, the upper one worked (didn't try the other one). Thanks a ton.

The rate was in cause that was the output of "cvt 1920 1080 60". I was just following what I found online.

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 77,699

Re: [SOLVED] Xrandr mode stopped working after update

What I meant was why you needed to add that resolution instead of obtaining it from the EDID.
Does the output officially support it? Does the GPU driver filter it?
(check the Xorg log on either)

Please always remember to mark resolved threads by editing your initial posts subject - so others will know that there's no task left, but maybe a solution to find.
Thanks.

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How to upload text · How to boot w/o GUI · Disable Windows Fast-Start! · Fix your xinitrc

m73

Member

Registered: 2012-06-04

Posts: 13

Re: [SOLVED] Xrandr mode stopped working after update

Hm...I only see EDID mentioned once in the Xorg log, supposedly making a modeline for my primary screen (1920x1080). There's no mention of DP2-3 (which is my external monitor, given by xrandr). DP2-3 doesn't have any 1920x1080 option as shown by the xrandr output, only lower. The screen resolution is 1920x1080 though. I assumed it just wasn't listed because I am using a VGA cable. I'm planning on getting a displayport cable later. Maybe then it'll show by default.

m73

Member

Registered: 2012-06-04

Posts: 13

Re: [SOLVED] Xrandr mode stopped working after update

Actually, I ended up using the output of "cvt 1920 1080 50":

Modeline "1920x1080_50.00"  141.50  1920 2032 2232 2544  1080 1083 1088 1114 -hsync +vsync

Which worked. Seth's rb2 made the screen dark in places and rb1 one didn't fill in the screen properly.