Xorg output hot-plug not working

[wolf <wolf@wolfsden.cz>]

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Hello,

for quite some time now I am trying to figure out how to get hot-plugging of
Xorg outputs working.  When I connect my USB-C docking station to my laptop, the
outputs DisplayPort-3 (and -4) are not showing up in xrandr.

However, when I restart the X server (while the dock is still connected), the
outputs are visible and usable.  Under Alpine linux, even the hot-plugging works
correctly.  Therefore it does not look like hardware nor driver issue.  But I
have no idea how to debug this further.  Would anyone how any ideas what could
be the cause and how could I fix this?

I did attach my configuration, but I believe I am not doing anything special.

Thank you,
W.

-- 
There are only two hard things in Computer Science:
cache invalidation, naming things and off-by-one errors.

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(use-modules (facts test)
	     (wn utils))

(use-modules (gnu)
	     (gnu packages certs)
	     (gnu packages linux)
	     (gnu packages gnome)
	     (gnu packages ssh)
	     (gnu packages xorg)
	     (gnu services)
	     (gnu services desktop)
	     (gnu services networking)
	     (gnu services ssh)
	     (gnu services xorg)
	     (nongnu packages linux)
	     (nongnu system linux-initrd))

(define custom-linux-lts
  (corrupt-linux linux-libre-5.15 #:configs '("CONFIG_MT7921E=m")))

(define %system
  (operating-system
   (host-name %wn/system)
   (locale "en_US.utf8")
   (timezone "Europe/Prague")

   (kernel custom-linux-lts)
   (kernel-arguments (delete "quiet"
			     %default-kernel-arguments))
   (initrd microcode-initrd)
   (firmware (list linux-firmware))

   (mapped-devices (list (mapped-device (source (uuid (list-ref %wn/luks-uuids 0)))
					(target (wn/luks-name %wn/system 0))
					(type luks-device-mapping))
			 (mapped-device (source (wn/vg-name %wn/system 0))
					(targets (list (wn/vg-part-name %wn/system 0 "swap")
						       (wn/vg-part-name %wn/system 0 "root")))
					(type lvm-device-mapping))))

   (file-systems (cons* (file-system (device (wn/vg-dev-for %wn/system 0 "root"))
				     (mount-point "/")
				     (type "btrfs")
				     (dependencies mapped-devices))
			(file-system (device (uuid (list-ref %wn/boot-uuids 0) 'fat))
				     (mount-point "/boot/efi0")
				     (type "vfat"))
			%base-file-systems))

   (swap-devices (list (swap-space (target (wn/vg-dev-for %wn/system 0 "swap"))
				   (dependencies mapped-devices))))

   (bootloader (bootloader-configuration (bootloader grub-efi-removable-bootloader)
					 (targets '("/boot/efi0"))))

   (users (cons* (user-account (name "wolf")
			       (group "wolf")
			       (uid 1000)
			       (supplementary-groups '("wheel"
						       "audio" "video"
						       "kvm")))
		 %base-user-accounts))

   (groups (cons* (user-group (name "wolf")
			      (id 1000))
		  %base-groups))

   (packages (cons* nss-certs

		    gnome

		    %base-packages))

   (services (cons*
	      (service static-networking-service-type
		       (list (static-networking
			      (addresses
			       (list (network-address
				      (device "enp4s0")
				      (value "192.168.0.130/24"))))
			      (routes
			       (list (network-route
				      (destination "default")
				      (gateway "192.168.0.1"))))
			      (name-servers '("192.168.0.1")))))

	      (service openssh-service-type
		       (openssh-configuration
			(openssh openssh-sans-x)
			(password-authentication? #f)
			(permit-root-login #t)
			(authorized-keys
			 `(("root" ,(local-file "files/wolf_ws.pub"))
			   ("wolf" ,(local-file "files/wolf_ws.pub"))))))

	      (modify-services %desktop-services
			       (delete network-manager-service-type)
			       (delete wpa-supplicant-service-type)
			       (guix-service-type
				config =>
				(guix-configuration
				 (inherit config)
				 (authorized-keys
				  (append `(,(local-file "/etc/guix/signing-key.pub"))
					  %default-authorized-guix-keys)))))))))

(list (machine
       (operating-system %system)
       (environment managed-host-environment-type)
       (configuration (machine-ssh-configuration
		       (host-name "192.168.0.130")
		       (system "x86_64-linux")
))))

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