Periodic display output freezing on the latest CachyOS build. It appears to be a DCN crash. No kernel panic and audio continues normally. journalctl -b -1 -k | grep -i “amdgpu” reveals nothing out of the ordinary. cachyos-bugreport.sh had a couple of oddities:
systemd-journald[775]: Time jumped backwards, rotating
Failed to open /dev/dri/renderD129 device (No such device)
atomic commit failed: Permission denied
switching to 6.19 lts resolved the issue.
Adding a data point to the kernel 7.0 AMD display issues. This is a different symptom class than the unresponsive-display reports, but same kernel and likely related underlying DCN regression.
System:
CachyOS, kernel linux-cachyos 7.0.1-1
KDE Plasma 6.6.4 / KDE Frameworks 6.25 / Wayland session
AMD Radeon RX 6950 XT (RDNA2)
mesa 26.0.5-4 / lib32-mesa 26.0.5-2
Display: Gigabyte M27Q X (1440p, 240Hz, FreeSync, 48-240Hz VRR range), connected via DisplayPort, no adapter
Symptoms on kernel 7.0.1-1:
kscreen-doctor -o reports Vrr: incapable for the connected DP output, even with a fullscreen application active.
KDE System Settings, Display Configuration no longer shows the Adaptive Sync option at all.
KWin support information reports Adaptive Sync: incapable.
Constant cursor-independent flicker (two thin horizontal black lines) in the panel strut region of the desktop. Persists across reboots, plasmashell restarts, and panel visibility changes. Setting the VRR policy to “Never” via kscreen-doctor output.DP-3.vrrpolicy.never does not change the symptom, indicating the redraws originate below the KWin/KDE layer. Likely shares root cause with the VRR detection failure rather than being downstream of it, since both are present from first boot of 7.0.1-1 and neither responds to userspace mitigation.
Critical diagnostic: the kernel itself sees VRR correctly:
$ sudo cat /sys/kernel/debug/dri/1/DP-3/vrr_range
Min: 48
Max: 240
This indicates the regression is in the kernel-to-userspace property exposure path (likely DCN-side), not in the kernel’s underlying display detection layer. The data is present at the DRM debugfs interface but is not being surfaced through the properties that compositors query.
Prior working state: VRR was confirmed functional on this exact hardware and display combination on the previous CachyOS kernel. Don’t have the exact prior version logged, but it was working through early April 2026 prior to the 7.0 rollout. Kernel 7.0.1-1 was installed 2026-04-23, and symptoms were present from first boot of 7.0.
Workaround: Have not yet tested booting linux-cachyos-lts to confirm it restores VRR detection, but other reports in this thread indicate LTS resolves the broader 7.0 AMD display issues. Will follow up with confirmation if/when I boot LTS.
Happy to provide additional logs, dmesg output, full kscreen-doctor -o output, or test patches if useful.