### Additional regression testing across kernels Further controlled testing performed.
Hardware: - AMD Radeon R9 380 (Tonga) - HDMI direct connection - X11 session - UEFI mode - CSM and Secure Boot tested both enabled and disabled Boot parameters used for consistency: quiet splash amdgpu.si_support=1 radeon.si_support=0 amdgpu.runpm=0 Test matrix results: Kernel 6.10.0: - Cold boot: OK - First suspend/resume: OK - Second suspend/resume: FAIL (black screen, frozen keyboard, requires hard reset) Kernel 6.12.74: - Same behavior as 6.10 - First suspend works - Second suspend consistently fails Kernel 6.13.12 (mainline): - Behavior similar to 6.12 (under continued testing) Kernel 6.14.x: - Resume reliability degraded further - HDMI instability observed even on first resume Kernel 6.17.0-14 (Ubuntu 24.10 base): - Suspend often fails even on first resume - EDID read errors logged: amdgpu: *ERROR* HDMI-A-1: probed a monitor but no|invalid EDID Important observation: The issue is reproducible and follows a pattern: - First suspend in a fresh boot session usually succeeds. - Subsequent suspend cycles consistently fail. This suggests a possible state handling or DC reinitialization issue in the HDMI pipeline. Cold boot always restores normal video. Hard reset required after failure. This is not a random freeze — it appears to be a deterministic multi- suspend regression affecting EDID re-detection. Further logs can be provided if requested. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2142389 Title: amdgpu (R9 380) fails to resume from suspend (deep sleep) – black screen, requires hard reboot To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2142389/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
