Yeah, I already have all those settings off. And like I said, after few minutes of random brightness, I hear sound of device connected and it stabilizes again, maybe that'd be a clue.
I've been trying to fix this with AI, this is the summary I asked it to generate on all we tried: Issue: Random Display Handshake Loss on Intel iGPU (Raptor Lake) Environment: Ubuntu 26.04 (Wayland), Dell Pro 14, External 1440p Monitor. Symptom: Random black screen flashes, followed by a "device connected" sound. Windows remain in place (Compositor does not crash). 1. Key Log Evidence GPU Texture Failure (Primary Clue): gnome-shell: Failed to create offscreen effect framebuffer: Failed to create texture 2d due to size/format constraints GJS Race Condition: gnome-shell: Object Gjs_ui_popupMenu_PopupMenuItem has been already disposed — impossible to access it. I/O Interference: fstrim.service: Consumed 2.671s CPU time over 2min 12.217s wall clock time (Flicker often coincides with high I/O maintenance). Process Spawning Delays: systemd: Started ptyxis-spawn-xxx.scope (Log timestamp matches the moment display recovery occurs). 2. Hypothesized Root Cause A deadlock occurs between the Intel i915 driver and GNOME Shell during high-resolution texture allocation or power-state transitions. The iGPU fails to allocate the framebuffer for shell effects (blur/animations), causing a display reset. 3. Tested Configurations (Unsuccessful) The following kernel parameters and settings were applied but did not fully resolve the flickering: Disabling PSR/DC States: i915.enable_psr=0, i915.enable_dc=0 Disabling Power Saving: i915.enable_fbc=0, pcie_aspm=off, i915.enable_dpst=0 C-State Limiting: intel_idle.max_cstate=1 (System often ignores this, defaulting to C9). GPU Scheduling: i915.enable_guc=3 Software Tweaks: Disabling GNOME animations, increasing vm.max_map_count, and setting powerprofilesctl to performance. 4. Behavior Notes The issue appears "random" but is likely tied to DPST or C-state transitions triggering during UI updates. The hardware link drops (HDMI/DP handshake lost), but the user session remains active. Hope that helps! -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2150784 Title: screen freeze - brightness changing To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+bug/2150784/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
