RX 6800: AMDGPU driver seems to crash when trying to enable 3rd monitor

Brief summary of the problem:

Unable to enable 3rd monitor in wayland nor X11 mode. Results in a driver crash of some sort.

(This is for helping with search):

[   72.372081] [drm] DM_MST: starting TM on aconnector: 000000007a6f95e4 [id: 99]
[   72.386252] [drm] DM_MST: stopping TM on aconnector: 000000007a6f95e4 [id: 99]
[   72.993848] [drm] perform_link_training_with_retries: Link training attempt 1 of 4 failed
[   73.284383] [drm] Failed to updateMST allocation table forpipe idx:2
[   73.463027] [drm] DM_MST: starting TM on aconnector: 000000007a6f95e4 [id: 99]
[   80.676339] [drm:drm_dp_send_link_address] *ERROR* Sending link address failed with -5
[   80.974217] [drm] amdgpu_dm_irq_schedule_work FAILED src 12

Hardware description:

• CPU: AMD Ryzen 5800X
• GPU: AMD Radeon RX 6800
• System Memory: 16GB of DDR4 3600Mhz
• Display(s): BenQ Zowie XL2430 (1080p), DELL U2414H (1080p), DELL U2415 (1920x1200)
• Type of Diplay Connection: All are connected via Display-Port

System information:

• Distro name and Version: Gentoo, updated portage tree as of today
• Kernel version: 5.10.27 (tested also 5.12.10, same result)
• AMD package version: No package
• MESA package version: 21.1.1 (tried 21.1.2 with the same result)

emerge info:

Portage 3.0.18 (python 3.9.4-final-0, default/linux/amd64/17.1/desktop/plasma, gcc-10.3.0, glibc-2.33, 5.10.27-gentoo-x86_64 x86_64)
=================================================================
System uname: Linux-5.10.27-gentoo-x86_64-x86_64-AMD_Ryzen_7_5800X_8-Core_Processor-with-glibc2.33
KiB Mem:    16389196 total,    191572 free
KiB Swap:   35651580 total,  35649788 free
Timestamp of repository gentoo: Fri, 11 Jun 2021 06:00:01 +0000
Head commit of repository gentoo: 613c3dd5dc4c96c93eaa06af6a65f2e8571bc987
Head commit of repository genpi-tools: a177eba5f060cb23d1812c04e970e4af872cb3a6

Timestamp of repository plex-overlay: Wed, 09 Jun 2021 18:35:10 +0000
Head commit of repository plex-overlay: 53da96c4332759179cc936497937b07a950f2894

sh bash 5.1_p8
ld GNU ld (Gentoo 2.35.2 p1) 2.35.2
app-shells/bash:          5.1_p8::gentoo
dev-lang/perl:            5.32.1::gentoo
dev-lang/python:          2.7.18_p9::gentoo, 3.8.9_p2::gentoo, 3.9.4_p1::gentoo
dev-lang/rust:            1.51.0-r2::gentoo
dev-util/cmake:           3.18.5::gentoo
sys-apps/baselayout:      2.7::gentoo
sys-apps/openrc:          0.42.1-r1::gentoo
sys-apps/sandbox:         2.24::gentoo
sys-devel/autoconf:       2.13-r1::gentoo, 2.69-r5::gentoo
sys-devel/automake:       1.16.3-r1::gentoo
sys-devel/binutils:       2.35.2::gentoo
sys-devel/gcc:            10.3.0::gentoo
sys-devel/gcc-config:     2.4::gentoo
sys-devel/libtool:        2.4.6-r6::gentoo
sys-devel/make:           4.3::gentoo
sys-kernel/linux-headers: 5.10::gentoo (virtual/os-headers)
sys-libs/glibc:           2.33::gentoo
Repositories:

gentoo
    location: /var/db/repos/gentoo
    sync-type: rsync
    sync-uri: rsync://rsync.gentoo.org/gentoo-portage
    priority: -1000
    sync-rsync-extra-opts: 
    sync-rsync-verify-jobs: 1
    sync-rsync-verify-metamanifest: yes
    sync-rsync-verify-max-age: 24

crossdev
    location: /var/db/repos/crossdev
    masters: gentoo genpi-tools

genpi-tools
    location: /var/db/repos/sakaki-tools
    sync-type: git
    sync-uri: https://github.com/GenPi64/genpi-tools.git
    masters: gentoo

plex-overlay
    location: /var/db/repos/plex-overlay
    sync-type: git
    sync-uri: https://github.com/gentoo-mirror/plex-overlay.git
    masters: gentoo

ACCEPT_KEYWORDS="amd64"
ACCEPT_LICENSE="@FREE"
CBUILD="x86_64-pc-linux-gnu"
CFLAGS="-march=native -O2 -pipe"
CHOST="x86_64-pc-linux-gnu"
CONFIG_PROTECT="/etc /usr/share/config /usr/share/gnupg/qualified.txt"
CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/dconf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo"
CXXFLAGS="-march=native -O2 -pipe"
DISTDIR="/var/cache/distfiles"
ENV_UNSET="CARGO_HOME DBUS_SESSION_BUS_ADDRESS DISPLAY GOBIN GOPATH PERL5LIB PERL5OPT PERLPREFIX PERL_CORE PERL_MB_OPT PERL_MM_OPT XAUTHORITY XDG_CACHE_HOME XDG_CONFIG_HOME XDG_DATA_HOME XDG_RUNTIME_DIR"
FCFLAGS="-march=native -O2 -pipe"
FEATURES="assume-digests binpkg-docompress binpkg-dostrip binpkg-logs binpkg-multi-instance buildpkg config-protect-if-modified distlocks ebuild-locks fixlafiles ipc-sandbox merge-sync multilib-strict network-sandbox news nostrip parallel-fetch parallel-install pid-sandbox preserve-libs protect-owned qa-unresolved-soname-deps sandbox sfperms strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync xattr"
FFLAGS="-march=native -O2 -pipe"
GENTOO_MIRRORS="https://mirror.eu.oneandone.net/linux/distributions/gentoo/gentoo/ https://ftp.snt.utwente.nl/pub/os/linux/gentoo"
LANG="en_US.utf8"
LDFLAGS="-Wl,-O1 -Wl,--as-needed"
MAKEOPTS="-j16 -l16"
PKGDIR="/var/cache/binpkgs"
PORTAGE_BINHOST="https://mirror.samip.fi/pub/dist/gentoo-amd64-binhost/"
PORTAGE_CONFIGROOT="/"
PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --omit-dir-times --compress --force --whole-file --delete --stats --human-readable --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages --exclude=/.git"
PORTAGE_TMPDIR="/var/tmp"
USE="X a52 aac acl acpi activities alsa amd64 berkdb bluetooth branding bzip2 cairo cdda cdr cli crypt dbus declarative dri dts dvd dvdr elogind emboss encode exif flac fortran gdbm gif gpm gtk gui iconv icu ipv6 jpeg kde kipi kwallet lcms libglvnd libnotify libtirpc mad mng mp3 mp4 mpeg multilib ncurses nls nptl ogg opengl openmp openssl pam pango pcre pcsc-lite pdf phonon plasma png policykit ppds pulseaudio qml qt5 readline samba sdl seccomp semantic-desktop spell split-usr ssl startup-notification svg tcpd tiff truetype udev udisks unicode upower usb vdpau vorbis wayland widgets wxwidgets x264 xattr xcb xml xv xvid zlib" ABI_X86="64" ADA_TARGET="gnat_2018" ALSA_CARDS="ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1x ens1370 ens1371 es1938 es1968 fm801 hda-intel intel8x0 intel8x0m maestro3 trident usb-audio via82xx via82xx-modem ymfpci" APACHE2_MODULES="authn_core authz_core socache_shmcb unixd actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache cgi cgid dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" CALLIGRA_FEATURES="karbon sheets words" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" CPU_FLAGS_X86="aes avx avx2 f16c fma3 mmx mmxext pclmul popcnt rdrand sha sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock greis isync itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf skytraq superstar2 timing tsip tripmate tnt ublox ubx" GRUB_PLATFORMS="efi-64" INPUT_DEVICES="evdev libinput" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" LUA_SINGLE_TARGET="lua5-1" LUA_TARGETS="lua5-1" OFFICE_IMPLEMENTATION="libreoffice" PHP_TARGETS="php7-3 php7-4" POSTGRES_TARGETS="postgres10 postgres11" PYTHON_SINGLE_TARGET="python3_9" PYTHON_TARGETS="python2_7 python3_8 python3_9" QEMU_USER_TARGETS="aarch64 arm mips" RUBY_TARGETS="ruby26" USERLAND="GNU" VIDEO_CARDS="amdgpu radeonsi" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq proto steal rawnat logmark ipmark dhcpmac delude chaos account"
Unset:  CC, CPPFLAGS, CTARGET, CXX, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LC_ALL, LINGUAS, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS, RUSTFLAGS

How to reproduce the issue:

1. Install Gentoo according to handbook normally.
2. Configure kernel with support for GPU because support for it is not enabled by default.
3. Install KDE desktop environment, with the usage of kde profile with openrc.
4. Have it work for weeks, and after some weeks it will not want to work on wayland nor X11 (it was working previously on Wyland only).

Attached files:

• dmesg log: dmesg.log
• Xorg log: Xorg.0.log
• make.conf: make.conf