Grub customizer can do much more and was made a lot time ago

I don’t think updating arch packages destroys displays) Plus new display should have protaction against this type of bugs

OS update can’t break hardware, so likely you damaged matrix connector on battery replace and now it died.

I think the best way is using live debian image with Wayland cage. User can change something, but it will be lost on restart. Debian supports plymouth out-of-the-box if enabled in grub.

This is server config

$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet [REDACTED]/32 scope global lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host noprefixroute 
       valid_lft forever preferred_lft forever
2: enp6s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether [REDACTED] brd ff:ff:ff:ff:ff:ff
    inet [REDACTED]/30 brd [REDACTED] scope global dynamic enp6s0
       valid_lft 327sec preferred_lft 327sec
    inet6 fe80::8e0:afff:feae:17cf/64 scope link 
       valid_lft forever preferred_lft forever
3: wlp5s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether [REDACTED] brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.1/24 brd 192.168.0.255 scope global wlp5s0
       valid_lft forever preferred_lft forever
    inet6 fe80::1291:d1ff:fe5a:2af8/64 scope link 
       valid_lft forever preferred_lft forever
4: virbr1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 52:54:00:cf:c8:59 brd ff:ff:ff:ff:ff:ff
    inet 192.168.2.1/24 brd 192.168.2.255 scope global virbr1
       valid_lft forever preferred_lft forever
5: virbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 52:54:00:bb:da:14 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.1/24 brd 192.168.1.255 scope global virbr0
       valid_lft forever preferred_lft forever
6: vnet0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master virbr0 state UNKNOWN group default qlen 1000
    link/ether fe:54:00:ec:b8:55 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::fc54:ff:feec:b855/64 scope link 
       valid_lft forever preferred_lft forever
7: wg0: <POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1420 qdisc noqueue state UNKNOWN group default qlen 1000
    link/none 
    inet 10.0.1.1/24 scope global wg0
       valid_lft forever preferred_lft forever

# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         [REDACTED]    0.0.0.0         UG    0      0        0 enp6s0
10.0.1.0        0.0.0.0         255.255.255.0   U     0      0        0 wg0
[REDACTED]    0.0.0.0         255.255.255.252 U     0      0        0 enp6s0
192.168.0.0     0.0.0.0         255.255.255.0   U     0      0        0 wlp5s0
192.168.1.0     0.0.0.0         255.255.255.0   U     0      0        0 virbr0
192.168.2.0     0.0.0.0         255.255.255.0   U     0      0        0 virbr1

# iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination         

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination         

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination         
# iptables -L -t nat
Chain PREROUTING (policy ACCEPT)
target     prot opt source               destination         

Chain INPUT (policy ACCEPT)
target     prot opt source               destination         

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination         

Chain POSTROUTING (policy ACCEPT)
target     prot opt source               destination         
MASQUERADE  all  --  anywhere             anywhere            

Is it possible on KDE Plasma?

I set modified EDID in GRUB. I have only 1 display.

I added new refresh rate for testing, but after enabling it I just get black screen. How to fix this issue?

SDDM main process is running as root and ignores all policies. So only way is modifying SDDM source code(

In this guide author dumped edid from disaplay and then loaded it without any modifications. So after reloading edid you can choose any resolution? Or I understood something wrong?

Thank you, it works! But I got weird behavior:

1. User sddm also cannot execute poweroff (it is ok) but if I press shutdown button in sddm it will poweroff (not ok).
2. If I press shut down in KDE Plasma I will get black screen and no sddm (I can restart it with systemctl restart sddm from tty and it will work again) How can I fix this bugs?

I think this is for applications not for graphical server

They all operates some way through systemd, so if operation is disabled via policy you cannot bypass it.

sasha@fedora:~$ /sbin/halt
Call to Halt failed: Interactive authentication required.

No, this is not possible. Virt-manager is just a GUI over libvirt. For now libvirt doesn’t support USB passthrought by port id, only by device id (which changes on each plug) or vendor id.

I tried this, didn’t help.

I added logs to post

I have R9 280

X server isn’t starting

Kernel driver is loaded

# lsmod | grep radeon
radeon               1888256  9
video                  77824  2 amdgpu,radeon
i2c_algo_bit           12288  2 amdgpu,radeon
drm_suballoc_helper    12288  2 amdgpu,radeon
drm_display_helper    266240  2 amdgpu,radeon
drm_ttm_helper         12288  2 amdgpu,radeon
ttm                   102400  3 amdgpu,radeon,drm_ttm_helper
drm_kms_helper        253952  3 drm_display_helper,amdgpu,radeon
drm                   749568  16 gpu_sched,drm_kms_helper,drm_exec,drm_suballoc_helper,drm_display_helper,drm_buddy,amdgpu,radeon,drm_ttm_helper,ttm,amdxcp