DisplayPort diasy-chain fails on reconfiguration
Description:
I have two Lenovo ThinkVision P24h-10 connected to a ThinkPad T480s. The ThinkPad is connected to Monitor 1 by USB-C. Monitor 2 is connected to Monitor 1 via DisplayPort daisy chain.
ThinkPad --usb-c--> Monitor1 --DP--> Monitor2
When I first start the computer, all screens show the same image. Once booted I run:
xrandr --output eDP1 --auto --output DP2-8 --left-of eDP1 --auto --output DP2-1-8 --left-of DP2-8 --auto
This works perfectly and all three monitors show individual desktops. I'm able to move windows independently between screens.
If I then disconnects the usb-c cable or run:
xrandr --output eDP1 --auto --output DP2-8 --off --output DP2-1-8 --off
I'm no longer able to configure Monitor 2 (the one connected via DP daisy chain. Monitor 1 connected via USB-C still works.
If I run my initial configuration command above I'm greeted by:
xrandr: Configure crtc 1 failed
I have tried multiple xrandr commands but without success. The only solution that seems to work is rebooting.
Package and system information:
uname -a
Linux archlinux 5.4.8-arch1-1 #1 SMP PREEMPT Sat, 04 Jan 2020 23:46:18 +0000 x86_64 GNU/Linux
xorg-server 1.20.6-3
xorg-xrandr 1.5.1-1
Verbose xrandr output:
xrandr --output eDP1 --auto --output DP2-8 --left-of eDP1 --auto --output DP2-1-8 --left-of DP2-8 --auto --verbose
screen 0: 7680x1440 2032x381 mm 96.00dpi
crtc 0: 2560x1440 60.00 +5120+0 "eDP1"
crtc 1: 2560x1440 59.95 +2560+0 "DP2-8" "DP2-1-8"
xrandr: Configure crtc 1 failed
crtc 0: disable
crtc 1: disable
crtc 2: disable
crtc 3: disable
screen 0: revert
crtc 0: revert
crtc 1: revert
crtc 2: revert
crtc 3: revert
Steps to reproduce:
Configure screens:
xrandr --output eDP1 --auto --output DP2-8 --left-of eDP1 --auto --output DP2-1-8 --left-of DP2-8 --auto
Disconnect screens or deconfigure:
xrandr --output eDP1 --auto --output DP2-8 --off --output DP2-1-8 --off
Try to reconfigure:
xrandr --output eDP1 --auto --output DP2-8 --left-of eDP1 --auto --output DP2-1-8 --left-of DP2-8 --auto
Error:
xrandr: Configure crtc 1 failed