I experience the same on my system, RX 7800 XT and Ryzen 5 5600, Ubuntu 26.04 + 1440p + 1080p monitor setup It comes out faster and more frequently when I hog the CPU, for example with stress --cpu 12 and moving some windows or enabling and disabling night light. Doesn't happen on weston or x11 session, however its mostly sure a kernel regression, as I tested the latest mainline 7.2.6 and Ubuntu's 7.0.0.34 and everything is fine here. The only different thing is the following kernel log line at startup when booting on the buggy kernel [ 16.477207] amdgpu 0000:2d:00.0: [drm] REG_WAIT timeout 1us * 100 tries - dcn32_program_compbuf_size line:148 I also tried my Thinkpad L15 which has an AMD APU Pro 5650u, its still present here but less noticeable even with huge CPU load. Found this on amdgpu drm bugzilla https://gitlab.freedesktop.org/drm/amd/-/work_items/5952 -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2169181 Title: Visual background flickering and pixel artifacts after updating to kernel 7.0.0-38 (regression from 7.0.0-34) | Ubuntu 26.04 | AMD Radeon RX 9060 Status in linux package in Ubuntu: Confirmed Bug description: I am experiencing intermittent pixel corruption and flickering artifacts in the background/desktop UI after updating to kernel version 7.0.0-38. Behavior: Random pixels/artifacts briefly flicker in the background from time to time. This issue was NOT present in kernel 7.0.0-34. The issue started immediately after updating to kernel 7.0.0-38. CPU: AMD Ryzen 5 9600X (12) @ 5.49 GHz GPU: AMD Radeon RX 9060 XT 16 GB[Discrete] P.S. I was planning to upgrade to the 26.10 beta this weekend, but I will stay on Resolute to help resolve this issue with any testing you might need. Thank you very much. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-38-generic 7.0.0-38.38 ProcVersionSignature: Ubuntu 7.0.0-38.38-generic 7.0.14 Uname: Linux 7.0.0-38-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Thu Oct 1 18:29:50 2026 InstallationDate: Installed on 2026-08-31 (31 days ago) InstallationMedia: Ubuntu 26.04.1 LTS "Resolute Raccoon" - Release amd64 (20260826) IwDevWlp11s0Link: Not connected. MachineType: ASUS System Product Name ProcEnviron: LANG=es_ES.UTF-8 PATH=(custom, no user) SHELL=/bin/bash TERM=xterm-256color XDG_RUNTIME_DIR=<set> ProcFB: 0 amdgpudrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-38-generic root=UUID=1bdfa414-371c-4c93-9288-8cdc845cb610 ro quiet splash crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 02/25/2026 dmi.bios.release: 38.41 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 3841 dmi.board.asset.tag: Default string dmi.board.name: PRIME B650-PLUS WIFI dmi.board.vendor: ASUSTeK COMPUTER INC. dmi.board.version: Rev 1.xx dmi.chassis.asset.tag: Default string dmi.chassis.type: 3 dmi.chassis.vendor: Default string dmi.chassis.version: Default string dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr3841:bd02/25/2026:br38.41:svnASUS:pnSystemProductName:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnPRIMEB650-PLUSWIFI:rvrRev1.xx:cvnDefaultstring:ct3:cvrDefaultstring:skuSKU:pfaTobefilledbyO.E.M.: dmi.product.family: To be filled by O.E.M. dmi.product.name: System Product Name dmi.product.sku: SKU dmi.product.version: System Version dmi.sys.vendor: ASUS To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2169181/+subscriptions
суббота
пятница
[Bug 2163642] Re: Kernel panic "Attempted to kill the idle task" on AMD Opteron multi-node NUMA under KVM (6.8.0-137)
Hi Radovan, Yes, the stopper panic is definitely a secondary crash from the KVM oops. Notice the faulting address 0xfffb77e9d05d8b4c in kvm_replace_memslot - bit 50 is flipped from the canonical 0xffff range. Once that vCPU thread oopsed and tainted the kernel with 'D', corrupted structures were left behind. Surviving 6 days after an oops on a 4-node NUMA host is actually impressive, but the scheduler eventually trips over it during migrate_swap. The hpilo IO_PAGE_FAULT at 0xbde0e000 is a side effect - pstore ERST tried to save the oops into ACPI reserved memory and AMD-Vi blocked it. On the journal- no need for gigabytes of userspace noise, but pls attach the snippet from those ~4 minutes before the freeze. Curious if any RCU stalls, soft lockups, or MCEs showed up right before the console went down. As for srv05 and srv07, I'd just let them keep running their soak test. But IMHO, 21 days on srv04 vs 3d and 8d without the params speaks for itself. I'd just keep processor.max_cstate=1 idle=nomwait on prod hosts. -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2163642 Title: Kernel panic "Attempted to kill the idle task" on AMD Opteron multi- node NUMA under KVM (6.8.0-137) Status in linux package in Ubuntu: Confirmed Bug description: **Title:** Kernel panic "Attempted to kill the idle task" on AMD Opteron 6300 series (multi-node NUMA) under KVM load - linux 6.8.0-137-generic (24.04) **Summary:** On 5 out of 5 identical HP ProLiant DL385p Gen8 servers (AMD Opteron 6386 SE, 4 NUMA nodes each, running as KVM/libvirt hypervisors with multiple guest VMs), kernel panics with "Attempted to kill the idle task!" occurred within roughly 1 to 24 hours after upgrading from Ubuntu 22.04 (kernel 5.15.0-187-generic, stable in production for years) to Ubuntu 24.04 (kernel 6.8.0-137-generic) via do-release- upgrade. Pinning the boot kernel back to 5.15.0-187-generic (via GRUB_DEFAULT) while keeping the 24.04 userspace fully resolved the instability on all affected hosts, with no further crashes since. **Hardware:** - HP ProLiant DL385p Gen8, BIOS A28 (03/14/2018) - AMD Opteron 6386 SE, microcode 0x6000852 - 4 NUMA nodes per host - KVM/libvirt hypervisor, 9-20 guest VMs per host under production load (mixed Kubernetes control-plane/worker nodes, haproxy, monitoring, storage services) **Steps to reproduce:** 1. Fresh `do-release-upgrade` from 22.04 (5.15.0-187-generic) to 24.04 (6.8.0-137-generic) on the described hardware 2. Boot into 6.8.0-137-generic with multiple KVM guests running under moderate-to-high, mixed CPU/memory load 3. Panic occurs non-deterministically, anywhere from ~1 hour to ~24 hours after boot; not tied to any single reproducible user action **Observed panic signature (consistent across all 5 affected hosts):** ``` Kernel panic - not syncing: Attempted to kill the idle task! Call Trace: <TASK> ? multi_cpu_stop+0xa0/0x120 ? __pfx_multi_cpu_stop+0x10/0x10 cpu_stopper_thread+0x9c/0x170 ? __pfx_smpboot_thread_fn+0x10/0x10 smpboot_thread_fn+0xe3/0x1e0 kthread+0xf2/0x120 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x47/0x70 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 </TASK> ``` One instance on a related host (same hardware) additionally showed `membarrier_private_expedited+0x1cf/0x2d0` in RIP immediately preceding the panic. **Possible related upstream discussion:** A 2018 LKML thread by Matt Fleming (SUSE), "cpu stopper threads and load balancing leads to deadlock" (https://lkml.iu.edu/hypermail/linux/kernel/1804.2/01642.html), describes a closely matching mechanism: a CPU stopper thread entering idle/active load balancing while, concurrently, NUMA balancing on another CPU attempts to migrate a task via `stop_two_cpus()`, resulting in a deadlock over the stopper lock. Given that our affected hosts are multi-node NUMA systems (4 nodes) and the panic call trace centers on `cpu_stopper_thread`/`multi_cpu_stop`, this looks like a strong candidate mechanism, though we cannot confirm whether it is the same unresolved issue, a regression of a past fix, or a new but related bug in 6.8. **Workaround applied:** GRUB kernel pinning to boot `5.15.0-187-generic` while keeping the 24.04 userspace intact (`GRUB_DEFAULT` set to the jammy kernel's advanced boot entry ID, `update-grub`, reboot). All 5 hosts stable since applying this workaround. **Additional diagnostics performed:** - Hardware (BIOS version, CPU model, microcode) verified identical across all 5 affected hosts - Memtester (4GB sample, full test cycle) passed clean on the two hosts tested - HP Integrated Management Log (IML) reviewed on two hosts: one shows a documented Uncorrectable CPU Machine Check Exception from 2020 (Bank 0x04, both physical processors) - possibly a contributing factor for that specific host, but does not explain the same panic signature occurring on hosts without such MCE history - Network/bonding layers (LACP, active-backup) verified healthy and unrelated to the panics - `dmesg`/`journalctl` EDAC output shows no correctable/uncorrectable memory errors logged around panic times on the hosts checked **Please let me know what additional information (full dmesg, kernel config, /proc/cpuinfo, NUMA topology via `numactl --hardware`, etc.) would help diagnose this further.** --- ProblemType: Bug AlsaDevices: total 0 crw-rw---- 1 root audio 116, 1 Aug 18 15:57 seq crw-rw---- 1 root audio 116, 33 Aug 18 15:57 timer AplayDevices: Error: [Errno 2] No such file or directory: 'aplay' ApportVersion: 2.28.3-0ubuntu0.1 Architecture: amd64 ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord' AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: CRDA: N/A CasperMD5CheckResult: unknown CloudBuildName: server CloudSerial: 20240524 DistroRelease: Ubuntu 24.04 IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig' MachineType: HP ProLiant DL385p Gen8 Package: linux (not installed) PciMultimedia: ProcEnviron: LANG=C.UTF-8 PATH=(custom, no user) SHELL=/bin/bash TERM=xterm-256color ProcFB: ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-6.8.0-137-generic root=UUID=9d93cee9-3b2d-4aff-b422-59c0ba9a1198 ro console=ttyS0,115200n8 console=tty0 vga=normal nomodeset nointremap ProcVersionSignature: Ubuntu 6.8.0-137.137-generic 6.8.12 RelatedPackageVersions: linux-restricted-modules-6.8.0-137-generic N/A linux-backports-modules-6.8.0-137-generic N/A linux-firmware 20240318.git3b128b60-0ubuntu2.29 RfKill: Error: [Errno 2] No such file or directory: 'rfkill' Tags: cloud-image noble Uname: Linux 6.8.0-137-generic x86_64 UpgradeStatus: Upgraded to noble on 2026-08-13 (5 days ago) UserGroups: N/A _MarkForUpload: True dmi.bios.date: 03/14/2018 dmi.bios.vendor: HP dmi.bios.version: A28 dmi.chassis.type: 23 dmi.chassis.vendor: HP dmi.ec.firmware.release: 2.82 dmi.modalias: dmi:bvnHP:bvrA28:bd03/14/2018:efr2.82:svnHP:pnProLiantDL385pGen8:pvr:cvnHP:ct23:cvr:sku653203-B21: dmi.product.family: ProLiant dmi.product.name: ProLiant DL385p Gen8 dmi.product.sku: 653203-B21 dmi.sys.vendor: HP To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2163642/+subscriptions
[Bug 2169236] Re: HDMI A/V desync on Intel UHD 630 (Comet Lake) since 7.0.0-34, still present on 7.0.0-38
Further testing, 2026-10-10. Another HWE kernel update. After a normal reboot into the new kernel, HDMI A/V was late again (same ~2 s, HDMI only, Aux fine). Switched back to 7.0.0-31: desync still present, same as the 2026-10-02 test. A reboot does not clear it. Full Sony power-off and HDMI unplug for 10 seconds cleared it on the new kernel as well. Same recovery as on 31 and 38. Summary: - First seen after 7.0.0-34. - Reproduced on 34, 38, and the current kernel after a normal reboot. - Once the Sony is in the bad state, it survives reboot and kernel switches (including back to 31). - Cleared on every kernel tested only by a full sink power-off and cable reseat. - 7.0.0-31 is not immune once the link is stuck; it only looked clean on 2026-09-29. This looks like an i915 HDMI bring-up change from 7.0.0-34 that leaves the sink with a sticky A/V offset. The unplug is a recovery, not evidence that the kernel is unrelated. -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2169236 Title: HDMI A/V desync on Intel UHD 630 (Comet Lake) since 7.0.0-34, still present on 7.0.0-38 Status in linux package in Ubuntu: Incomplete Bug description: Regression on Ubuntu 24.04 HWE kernels (Linux Mint 22.2). Hardware: - Intel CometLake-S GT2 UHD Graphics 630 (8086:9bc8), i915 - HDMI-1 to Sony TV, 1920x1080 - Analog Aux is unaffected Last good: 7.0.0-31-generic First bad: 7.0.0-34-generic Still bad: 7.0.0-38-generic On 34 and 38, HDMI video freezes about 5 seconds at start, then voice is about 2 seconds late. Firefox, Brave, and Celluloid all show it. Aux stays in sync. PipeWire latency offset does not change it. 7.0.0-31 is clean with the same Xorg (2:21.1.12-1ubuntu1.8), so this is not the Xorg update from 2026-09-29. ubuntu-bug linux refused the report: "This does not seem to be an official Linux package" on linux-image-7.0.0-38-generic (Mint). --- ProblemType: Bug ApportVersion: 2.28.3-0ubuntu0.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: brett 2067 F.... pipewire brett 2070 F.... wireplumber /dev/snd/pcmC0D3p: brett 2067 F...m pipewire /dev/snd/seq: brett 2067 F.... pipewire CRDA: N/A CasperMD5CheckMismatches: ./boot/grub/efi.img CasperMD5CheckResult: fail CurrentDesktop: i3 DistroRelease: Linux Mint 22.2 InstallationDate: Installed on 2025-12-25 (285 days ago) InstallationMedia: Linux Mint 22.2 "Zara" - Release amd64 20250828 MachineType: Micro-Star International Co., Ltd. MS-7D82 Package: linux (not installed) ProcFB: 0 i915drmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-38-generic root=UUID=8f09b6c5-7d43-4a10-a1a1-8f954eef5146 ro quiet splash ProcVersionSignature: Ubuntu 7.0.0-38.38~24.04.4-generic 7.0.14 PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon. RelatedPackageVersions: linux-restricted-modules-7.0.0-38-generic N/A linux-backports-modules-7.0.0-38-generic N/A linux-firmware 20240318.git3b128b60.0ubuntu3.1 RfKill: 0: hci0: Bluetooth Soft blocked: yes Hard blocked: no Tags: zara Uname: Linux 7.0.0-38-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: N/A _MarkForUpload: True dmi.bios.date: 03/26/2026 dmi.bios.release: 5.19 dmi.bios.vendor: American Megatrends International, LLC. dmi.bios.version: 1.71 dmi.board.asset.tag: Default string dmi.board.name: PRO H410M-B (MS-7D82) dmi.board.vendor: Micro-Star International Co., Ltd. dmi.board.version: 1.0 dmi.chassis.asset.tag: Default string dmi.chassis.type: 3 dmi.chassis.vendor: Micro-Star International Co., Ltd. dmi.chassis.version: 1.0 dmi.modalias: dmi:bvnAmericanMegatrendsInternational,LLC.:bvr1.71:bd03/26/2026:br5.19:svnMicro-StarInternationalCo.,Ltd.:pnMS-7D82:pvr1.0:rvnMicro-StarInternationalCo.,Ltd.:rnPROH410M-B(MS-7D82):rvr1.0:cvnMicro-StarInternationalCo.,Ltd.:ct3:cvr1.0:skuDefaultstring:pfaDefaultstring: dmi.product.family: Default string dmi.product.name: MS-7D82 dmi.product.sku: Default string dmi.product.version: 1.0 dmi.sys.vendor: Micro-Star International Co., Ltd. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2169236/+subscriptions
[Bug 2169181] Re: Visual background flickering and pixel artifacts after updating to kernel 7.0.0-38 (regression from 7.0.0-34) | Ubuntu 26.04 | AMD Radeon RX 9060
I have the same problem, which started on 7.0.0.38 with Ubuntu 26.04. a RX 9060 XT and a Samsung TV connected in HDMI as monitor, 4k @ 60Hz. The horizontal "bar" so quickly disappears that it's barely visible. It covers like 50%-70% of the screen width, is usually located near the bottom of the screen, and has a height of 10% of the screen height. It's as if a "cloud" of random pixel was appearing in that zone, for a very, very short time. That happens about once or twice per hour, roughly. -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2169181 Title: Visual background flickering and pixel artifacts after updating to kernel 7.0.0-38 (regression from 7.0.0-34) | Ubuntu 26.04 | AMD Radeon RX 9060 Status in linux package in Ubuntu: Confirmed Bug description: I am experiencing intermittent pixel corruption and flickering artifacts in the background/desktop UI after updating to kernel version 7.0.0-38. Behavior: Random pixels/artifacts briefly flicker in the background from time to time. This issue was NOT present in kernel 7.0.0-34. The issue started immediately after updating to kernel 7.0.0-38. CPU: AMD Ryzen 5 9600X (12) @ 5.49 GHz GPU: AMD Radeon RX 9060 XT 16 GB[Discrete] P.S. I was planning to upgrade to the 26.10 beta this weekend, but I will stay on Resolute to help resolve this issue with any testing you might need. Thank you very much. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-38-generic 7.0.0-38.38 ProcVersionSignature: Ubuntu 7.0.0-38.38-generic 7.0.14 Uname: Linux 7.0.0-38-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Thu Oct 1 18:29:50 2026 InstallationDate: Installed on 2026-08-31 (31 days ago) InstallationMedia: Ubuntu 26.04.1 LTS "Resolute Raccoon" - Release amd64 (20260826) IwDevWlp11s0Link: Not connected. MachineType: ASUS System Product Name ProcEnviron: LANG=es_ES.UTF-8 PATH=(custom, no user) SHELL=/bin/bash TERM=xterm-256color XDG_RUNTIME_DIR=<set> ProcFB: 0 amdgpudrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-38-generic root=UUID=1bdfa414-371c-4c93-9288-8cdc845cb610 ro quiet splash crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 02/25/2026 dmi.bios.release: 38.41 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 3841 dmi.board.asset.tag: Default string dmi.board.name: PRIME B650-PLUS WIFI dmi.board.vendor: ASUSTeK COMPUTER INC. dmi.board.version: Rev 1.xx dmi.chassis.asset.tag: Default string dmi.chassis.type: 3 dmi.chassis.vendor: Default string dmi.chassis.version: Default string dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr3841:bd02/25/2026:br38.41:svnASUS:pnSystemProductName:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnPRIMEB650-PLUSWIFI:rvrRev1.xx:cvnDefaultstring:ct3:cvrDefaultstring:skuSKU:pfaTobefilledbyO.E.M.: dmi.product.family: To be filled by O.E.M. dmi.product.name: System Product Name dmi.product.sku: SKU dmi.product.version: System Version dmi.sys.vendor: ASUS To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2169181/+subscriptions
[Bug 2169319] Re: amdgpu: screen flashes at 120/144 Hz on RX 9060 XT (gfx1200), regression 7.0.0-34 -> 7.0.0-38
I have the same problem, which started on 7.0.0.38 with Ubuntu 26.04. a RX 9060 XT and a Samsung TV connected in HDMI as monitor, 4k @ 60Hz. The horizontal "bar" so quickly disappears that it's barely visible. It covers like 50%-70% of the screen width, is usually located near the bottom of the screen, and has a height of 10% of the screen height. It's as if a "cloud" of random pixel was appearing in that zone, for a very, very short time. That happens about once or twice per hour, roughly. -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2169319 Title: amdgpu: screen flashes at 120/144 Hz on RX 9060 XT (gfx1200), regression 7.0.0-34 -> 7.0.0-38 Status in linux package in Ubuntu: Confirmed Bug description: After upgrading to linux-image-7.0.0-38-generic, a DisplayPort monitor shows ~1 ms visual flashes (tearing-like) at 120 Hz and 144 Hz. 7.0.0-34-generic is clean at the same refresh rate with identical userspace. Hardware - GPU: AMD Radeon RX 9060 XT (gfx1200), PCI 1002:7590, driver amdgpu - Display: HWV ZQE-CAA, 3440x1440, 165 Hz native, DP-1, 10 bpc, no DSC - Session: GNOME Wayland (mutter 50.1), Mesa 26.0.8 Symptom - Brief flashes on pointer motion and small damage repaints (typing in a terminal, overview hover, mouse movement). GL apps make it more frequent; it still happens with all GPU apps closed. - Clean at 60 Hz and 100 Hz. Glitches at 120 Hz and 144 Hz. - Clean on the GDM greeter. Regression - 7.0.0-34-generic: clean at 144 Hz. 7.0.0-38-generic: glitches at 144 Hz. - Same mutter, Mesa and monitor on both; only the kernel changed. - A second machine (AMD iGPU, internal panel, 7.0.0-34) is unaffected; it has not run -38 yet. Ruled out (still glitches on -38) - Userspace mismatch after upgrade (rebooted after full-upgrade) - GNOME animations disabled - Hardware cursor plane disabled (MUTTER_DEBUG_DISABLE_HW_CURSORS=1, MUTTER_DEBUG_INHIBIT_HW_CURSOR=1, verified in gnome-shell environ) - Overlay planes (MUTTER_DEBUG_FORCE_KMS_MODE=simple, verified) - Link side: dp1 link_settings (4 lanes, 0x1e = HBR3), DSC state (off), max bpc (10), amdgpu_dm_capabilities and amdgpu_dm_dtn_log are identical between -34 and -38 at 144 Hz. No DP link-training/DSC errors in dmesg on either kernel. Suspect commits (from the linux 7.0.0-38.38 changelog, not bisected) 1. drm/amd/display: consolidate DCN vblank/flip handling onto ... 2. drm/amd/display: Fix DTB DTO updates breaking live pixel rate sources 3. drm/amd/display: Fix mem_type change detection for async flips 4. drm/amd/display: Handle struct drm_plane_state.ignore_damage_clips Attached: dp1-link, dm-capabilities and dtn for both kernels, modes-DP1.txt, monitor-edid-34.txt in all in file ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: xorg (not installed) ProcVersionSignature: Ubuntu 7.0.0-34.34-generic 7.0.14 Uname: Linux 7.0.0-34-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Fri Oct 2 18:38:04 2026 InstallationDate: Installed on 2025-02-22 (587 days ago) InstallationMedia: Ubuntu 24.04.2 LTS "Noble Numbat" - Release amd64 (20250215) ProcEnviron: LANG=en_US.UTF-8 PATH=(custom, no user) SHELL=/bin/zsh TERM=tmux-256color XDG_RUNTIME_DIR=<set> SourcePackage: xorg Symptom: display UpgradeStatus: Upgraded to resolute on 2026-10-02 (0 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2169319/+subscriptions
[Bug 2170396] Re: Lenovo Legion screen flickering on Kubuntu 26.04 (Fixed by lowering brightness / 165Hz conflict)
** Tags added: kernel-daily-bug -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2170396 Title: Lenovo Legion screen flickering on Kubuntu 26.04 (Fixed by lowering brightness / 165Hz conflict) Status in linux package in Ubuntu: New Bug description: I installed Kubuntu 26.04 on my Lenovo Legion laptop (NVIDIA graphics) and experienced severe screen flickering. Key behaviors observed: • The panel natively runs at 165.04Hz. • Forcing the refresh rate down to 60Hz via kscreen-doctor temporarily improved the flickering but did not resolve it. • Forcing "Discrete Graphics" in the BIOS resulted in a total black screen upon OS load. • Crucial Hardware Link: Lowering the screen brightness manually to 30% reduces the flickering to minimal/manageable levels, suggesting a power-delivery/backlight voltage or PWM conflict with the modern kernel's power-saving features. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-38-generic 7.0.0-38.38 ProcVersionSignature: Ubuntu 7.0.0-38.38-generic 7.0.14 Uname: Linux 7.0.0-38-generic x86_64 NonfreeKernelModules: nvidia_modeset nvidia ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: jgw 1549 F.... pipewire jgw 1561 F.... wireplumber /dev/snd/controlC0: jgw 1561 F.... wireplumber /dev/snd/seq: jgw 1549 F.... pipewire CasperMD5CheckResult: unknown CurrentDesktop: KDE Date: Fri Oct 9 19:23:43 2026 InstallationDate: Installed on 2026-10-07 (2 days ago) InstallationMedia: Kubuntu 26.04.1 LTS "Resolute Raccoon" - Release amd64 (20260826.1) MachineType: LENOVO 82TF ProcFB: 0 i915drmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-38-generic root=UUID=3ad3b9bb-66ac-4411-a956-601a55f3254c ro quiet splash pcie_aspm=off acpi_backlight=native PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon. SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 03/03/2025 dmi.bios.release: 1.58 dmi.bios.vendor: LENOVO dmi.bios.version: JYCN58WW dmi.board.asset.tag: No Asset Tag dmi.board.name: LNVNB161216 dmi.board.vendor: LENOVO dmi.board.version: SDK0T76461WIN dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: Legion S7 16IAH7 dmi.ec.firmware.release: 1.55 dmi.modalias: dmi:bvnLENOVO:bvrJYCN58WW:bd03/03/2025:br1.58:efr1.55:svnLENOVO:pn82TF:pvrLegionS716IAH7:rvnLENOVO:rnLNVNB161216:rvrSDK0T76461WIN:cvnLENOVO:ct10:cvrLegionS716IAH7:skuLENOVO_MT_82TF_BU_idea_FM_LegionS716IAH7:pfaLegionS716IAH7: dmi.product.family: Legion S7 16IAH7 dmi.product.name: 82TF dmi.product.sku: LENOVO_MT_82TF_BU_idea_FM_Legion S7 16IAH7 dmi.product.version: Legion S7 16IAH7 dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2170396/+subscriptions
[Bug 1690085] Re: Ryzen 1800X freeze - rcu_sched detected stalls on CPUs/tasks
Your business doesn't need another generic SEO package—it needs a plan that understands your market and speaks to your ideal customers. Web Founders USA is a results-focused Boutique SEO Agency helping businesses strengthen their search presence with tailored optimization and thoughtful strategy. We combine long-tail keyword targeting, topical authority development, content architecture, technical SEO, local search optimization, competitor gap research, internal linking, and relevant backlink building to help your website compete for valuable searches. By aligning search engine optimization with user experience and conversion opportunities, we aim to attract visitors who are genuinely interested in your services. Ready to make your website a stronger source of qualified leads? Contact Web Founders USA today for a personalized SEO strategy built around your business and growth priorities. For more info: https://www.webfoundersusa.com/service/seo- services/boutique-seo/ -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/1690085 Title: Ryzen 1800X freeze - rcu_sched detected stalls on CPUs/tasks Status in Linux: Expired Status in linux package in Ubuntu: Confirmed Bug description: Hi, We aregetting various kernel crash on a pretty new config. We're using Ryzen 1800X CPU with X370 Gaming Pro Carbon MB (7A32V1) using latest BIOS available (1.52) We are running Ubuntu 17.04 (amd64), we've tried different kernel version, native one and releases from http://kernel.ubuntu.com/~kernel-ppa/mainline/ too. Tested kernel version: native 17.04 kernel 4.10.15 Issues are the same, we're getting random freeze on the machine. Here is kern.log entry when happening : May 10 22:41:56 dev2 kernel: [24366.186246] INFO: rcu_sched detected stalls on CPUs/tasks: May 10 22:41:56 dev2 kernel: [24366.187618] 0-...: (1 GPs behind) idle=49b/1/0 softirq=28561/28563 fqs=913449 May 10 22:41:56 dev2 kernel: [24366.188977] (detected by 12, t=1860207 jiffies, g=10001, c=10000, q=4656) May 10 22:41:56 dev2 kernel: [24366.190344] Task dump for CPU 0: May 10 22:41:56 dev2 kernel: [24366.190345] swapper/0 R running task 0 0 0 0x00000008 May 10 22:41:56 dev2 kernel: [24366.190348] Call Trace: May 10 22:41:56 dev2 kernel: [24366.190354] ? native_safe_halt+0x6/0x10 May 10 22:41:56 dev2 kernel: [24366.190355] ? default_idle+0x20/0xd0 May 10 22:41:56 dev2 kernel: [24366.190358] ? arch_cpu_idle+0xf/0x20 May 10 22:41:56 dev2 kernel: [24366.190360] ? default_idle_call+0x23/0x30 May 10 22:41:56 dev2 kernel: [24366.190362] ? do_idle+0x16f/0x200 May 10 22:41:56 dev2 kernel: [24366.190364] ? cpu_startup_entry+0x71/0x80 May 10 22:41:56 dev2 kernel: [24366.190366] ? rest_init+0x77/0x80 May 10 22:41:56 dev2 kernel: [24366.190368] ? start_kernel+0x464/0x485 May 10 22:41:56 dev2 kernel: [24366.190369] ? early_idt_handler_array+0x120/0x120 May 10 22:41:56 dev2 kernel: [24366.190371] ? x86_64_start_reservations+0x24/0x26 May 10 22:41:56 dev2 kernel: [24366.190372] ? x86_64_start_kernel+0x14d/0x170 May 10 22:41:56 dev2 kernel: [24366.190373] ? start_cpu+0x14/0x14 May 10 22:44:56 dev2 kernel: [24546.188093] INFO: rcu_sched detected stalls on CPUs/tasks: May 10 22:44:56 dev2 kernel: [24546.189461] 0-...: (1 GPs behind) idle=49b/1/0 softirq=28561/28563 fqs=935027 May 10 22:44:56 dev2 kernel: [24546.190823] (detected by 14, t=1905212 jiffies, g=10001, c=10000, q=4740) May 10 22:44:56 dev2 kernel: [24546.192191] Task dump for CPU 0: May 10 22:44:56 dev2 kernel: [24546.192192] swapper/0 R running task 0 0 0 0x00000008 May 10 22:44:56 dev2 kernel: [24546.192195] Call Trace: May 10 22:44:56 dev2 kernel: [24546.192199] ? native_safe_halt+0x6/0x10 May 10 22:44:56 dev2 kernel: [24546.192201] ? default_idle+0x20/0xd0 May 10 22:44:56 dev2 kernel: [24546.192203] ? arch_cpu_idle+0xf/0x20 May 10 22:44:56 dev2 kernel: [24546.192204] ? default_idle_call+0x23/0x30 May 10 22:44:56 dev2 kernel: [24546.192206] ? do_idle+0x16f/0x200 May 10 22:44:56 dev2 kernel: [24546.192208] ? cpu_startup_entry+0x71/0x80 May 10 22:44:56 dev2 kernel: [24546.192210] ? rest_init+0x77/0x80 May 10 22:44:56 dev2 kernel: [24546.192211] ? start_kernel+0x464/0x485 May 10 22:44:56 dev2 kernel: [24546.192213] ? early_idt_handler_array+0x120/0x120 May 10 22:44:56 dev2 kernel: [24546.192214] ? x86_64_start_reservations+0x24/0x26 May 10 22:44:56 dev2 kernel: [24546.192215] ? x86_64_start_kernel+0x14d/0x170 May 10 22:44:56 dev2 kernel: [24546.192217] ? start_cpu+0x14/0x14 Depending on the kernel version, we've got NMI watchdog errors related to CPU stuck (mentioning the CPU core id, which is random). Crash is happening randomly, but in general after some hours (3-4h). Now, we've installed kernel 4.11.0-041100-generic #201705041534 this morning and waiting for crash... For now, the machine is not "used", at least, it's not CPU stressed... Thanks --- ApportVersion: 2.20.4-0ubuntu4 Architecture: amd64 DistroRelease: Ubuntu 17.04 InstallationDate: Installed on 2017-05-09 (1 days ago) InstallationMedia: Ubuntu-Server 17.04 "Zesty Zapus" - Release amd64 (20170412) Package: linux (not installed) ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=fr_FR.UTF-8 SHELL=/bin/bash Tags: zesty Uname: Linux 4.11.0-041100-generic x86_64 UnreportableReason: The running kernel is not an Ubuntu kernel UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: _MarkForUpload: True To manage notifications about this bug go to: https://bugs.launchpad.net/linux/+bug/1690085/+subscriptions
[Bug 1786013] Autopkgtest regression report (linux-restricted-modules-nvidia-6.8/6.8.0-1065.68~22.04.1+1)
All autopkgtests for the newly accepted linux-restricted-modules-nvidia-6.8 (6.8.0-1065.68~22.04.1+1) for jammy have finished running. The following regressions have been reported in tests triggered by the package: nvidia-graphics-drivers-470/470.256.02-0ubuntu0.22.04.6 (amd64) Please visit the excuses page listed below and investigate the failures, proceeding afterwards as per the StableReleaseUpdates policy regarding autopkgtest regressions [1]. https://ubuntu-archive-team.ubuntu.com/proposed- migration/jammy/update_excuses.html#linux-restricted-modules-nvidia-6.8 [1] https://documentation.ubuntu.com/project/SRU/howto/autopkgtest- failure/ Thank you! -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/1786013 Title: Packaging resync Status in linux package in Ubuntu: Fix Released Status in linux-azure package in Ubuntu: Fix Released Status in linux-azure-edge package in Ubuntu: Fix Released Status in linux source package in Precise: Fix Released Status in linux-azure source package in Precise: Won't Fix Status in linux-azure-edge source package in Precise: Won't Fix Status in linux source package in Trusty: Fix Released Status in linux-azure source package in Trusty: Fix Released Status in linux-azure-edge source package in Trusty: Won't Fix Status in linux source package in Xenial: Fix Released Status in linux-azure source package in Xenial: Fix Released Status in linux-azure-edge source package in Xenial: Fix Released Status in linux source package in Bionic: Fix Released Status in linux-azure source package in Bionic: Fix Released Status in linux-azure-edge source package in Bionic: Fix Released Status in linux source package in Cosmic: Fix Released Status in linux-azure source package in Cosmic: Fix Released Status in linux-azure-edge source package in Cosmic: Won't Fix Status in linux source package in Disco: Fix Released Status in linux-azure source package in Disco: Fix Released Status in linux-azure-edge source package in Disco: Won't Fix Bug description: Ongoing packaging resyncs. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1786013/+subscriptions
[Bug 2170215] Re: MT7921K (mt7921e) severe packet loss on 7.0.0-38, works on 7.0.0-34
Not a kernel bug. The packet loss was caused by a weak wireless backhaul between two TP-Link Deco mesh units. After connecting the units with an Ethernet cable, there is 0% packet loss on 7.0.0-38 over both Wi-Fi and Ethernet. Sorry for the noise. ** Changed in: linux (Ubuntu) Status: New => Invalid -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2170215 Title: MT7921K (mt7921e) severe packet loss on 7.0.0-38, works on 7.0.0-34 Status in linux package in Ubuntu: Invalid Bug description: After upgrading to Ubuntu 26.04.1 LTS, Wi-Fi on a MediaTek MT7921K (Gigabyte GC-WBAX1200, driver mt7921e) has heavy packet loss. Pinging the local router (signal -41 dBm, 2.4 GHz): - kernel 7.0.0-38-generic: ~55% packet loss, latency spikes up to 450 ms - kernel 7.0.0-34-generic: ~7% packet loss, normal latency On 5 GHz the loss on 7.0.0-38 is 45-60%. Other devices on the same network work without problems. Already tried without success: disable_aspm=1, Wi-Fi power save off, Bluetooth disabled, locking to a single BSSID. Workaround: booting 7.0.0-34-generic. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-38-generic 7.0.0-38.38 ProcVersionSignature: Ubuntu 7.0.0-38.38-generic 7.0.14 Uname: Linux 7.0.0-38-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: darko 4935 F.... wireplumber /dev/snd/controlC0: darko 4935 F.... wireplumber /dev/snd/seq: darko 4916 F.... pipewire CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Thu Oct 8 18:16:53 2026 InstallationDate: Installed on 2025-11-10 (332 days ago) InstallationMedia: Ubuntu 24.04.3 LTS "Noble Numbat" - Release amd64 (20250805.1) MachineType: Gigabyte Technology Co., Ltd. X570 AORUS PRO ProcEnviron: LANG=en_US.UTF-8 PATH=(custom, no user) SHELL=/bin/bash TERM=xterm-256color XDG_RUNTIME_DIR=<set> ProcFB: 0 nvidia-drmdrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-38-generic root=UUID=90ed7cdb-1a4d-4848-b867-9f9d86f55577 ro quiet splash crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M SourcePackage: linux UpgradeStatus: Upgraded to resolute on 2026-10-08 (0 days ago) dmi.bios.date: 03/22/2024 dmi.bios.release: 5.17 dmi.bios.vendor: American Megatrends International, LLC. dmi.bios.version: F38 dmi.board.asset.tag: Default string dmi.board.name: X570 AORUS PRO dmi.board.vendor: Gigabyte Technology Co., Ltd. dmi.board.version: Default string dmi.chassis.asset.tag: Default string dmi.chassis.type: 3 dmi.chassis.vendor: Default string dmi.chassis.version: Default string dmi.modalias: dmi:bvnAmericanMegatrendsInternational,LLC.:bvrF38:bd03/22/2024:br5.17:svnGigabyteTechnologyCo.,Ltd.:pnX570AORUSPRO:pvr-CF:rvnGigabyteTechnologyCo.,Ltd.:rnX570AORUSPRO:rvrDefaultstring:cvnDefaultstring:ct3:cvrDefaultstring:skuDefaultstring:pfaX570MB: dmi.product.family: X570 MB dmi.product.name: X570 AORUS PRO dmi.product.sku: Default string dmi.product.version: -CF dmi.sys.vendor: Gigabyte Technology Co., Ltd. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2170215/+subscriptions
четверг
[Bug 2165864] Re: Ethernet MAC address not set correctly after Thunderbolt dock hot-plug on Dell systems
Hi Acelan, Please help confirm the release plan for Reengade PTL. -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2165864 Title: Ethernet MAC address not set correctly after Thunderbolt dock hot-plug on Dell systems Status in linux package in Ubuntu: In Progress Status in linux-oem-6.17 package in Ubuntu: Invalid Status in linux-oem-7.0 package in Ubuntu: Invalid Status in linux source package in Noble: In Progress Status in linux-oem-6.17 source package in Noble: Won't Fix Status in linux-oem-7.0 source package in Noble: Invalid Status in linux source package in Resolute: In Progress Status in linux-oem-6.17 source package in Resolute: Invalid Status in linux-oem-7.0 source package in Resolute: In Progress Status in linux source package in Stonking: In Progress Status in linux-oem-6.17 source package in Stonking: Invalid Status in linux-oem-7.0 source package in Stonking: Invalid Bug description: [Impact] On Dell systems (CID: 202512-38196) with a Thunderbolt dock's Intel I225/I226 (igc) ethernet port, hot-plugging the dock can leave the ethernet interface non-functional or using the wrong MAC address. The dock's BIOS exposes a system MAC address through ACPI (\_SB.AMAC or \MACA objects) meant to override the NIC's own address, but the igc driver never reads it. The driver falls back to reading the MAC from NVM, which can race with the dock's own MAC copy timing or simply not match what the dock/BIOS expect, so the interface comes up with a stale or wrong MAC and networking fails. Failure rate on affected hardware: about 1 in 3 hot-plug cycles. Suspend/resume or cable bounce (CB/WB) works around it because the driver re-probes and picks up the right value on a later attempt. [Fix] Add ACPI-based MAC passthrough support to the igc driver. On probe, if the platform doesn't already hand the driver a MAC address, look up the \_SB.AMAC or \MACA ACPI objects. If a valid Ethernet MAC is found there, use it (mark it NET_ADDR_STOLEN) instead of falling back to the NVM read. If the objects don't exist or don't contain a valid MAC, the existing NVM read path is used unchanged, so unaffected hardware sees no behavior change. This also lets us drop two previous SAUCE patches that tried to fix the same failure by inserting a fixed delay (600ms, then 1000ms) before reading the NVM MAC on Thunderbolt-attached devices. Those were timing guesses and never fully closed the race; the ACPI passthrough reads the correctMAC directly instead of guessing how long to wait. Patches, in order: 1. Revert "UBUNTU: SAUCE: igc: Increase Thunderbolt MAC passthrough delay to 1000ms" 2. Revert "UBUNTU: SAUCE: igc: wait for the MAC copy when enabled MAC passthrough" 3. igc: Support ACPI-based MAC passthrough Patch 3 is posted upstream on the intel-wired-lan list (not yet merged): https://patchwork.ozlabs.org/project/intel-wired-lan/patch/20260823061006.344040-1-dima.ruinskiy@intel.com/ Or https://patchwork.ozlabs.org/project/intel-wired-lan/list?state=%2A&archive=both (search "igc: Support ACPI-based MAC passthrough") Note: the version carried in this branch is an earlier draft of the upstream patch (v1). The latest posted version (v3, dated 2026-08-22) additionally scopes the ACPI lookup to the I225/I226 device IDs used in docking stations only (via a new board_dock/is_dock flag), so it does not touch onboard I225/I226 NICs at all. We should pick up v3 once it lands, or apply the same device-ID scoping locally, to avoid the ACPI lookup running on non-dock onboard NICs. [Test Plan] 1. Connect an Ethernet cable to the Thunderbolt dock's ethernet port. 2. Boot the system with the dock disconnected. 3. Connect the dock to the system (hot-plug). 4. Check the ethernet interface comes up and has a stable, correct MAC address: $ ip link show <iface> $ dmesg | grep -i "igc.*MAC" 5. Repeat the hot-plug cycle at least 10 times. Without the patch: ethernet fails to come up or gets a wrong MAC on about 1 in 3 hot-plugs; recovers only after suspend/resume or an unplug/replug cycle. With the patch: dmesg shows "Using ACPI pass-thru MAC addr ..." on each hot-plug, and the interface consistently comes up with the correct MAC every time. [Where problems could occur] This touches the igc driver's probe path, which runs for every I225/I226 device, not only docked ones (the version currently in this branch does not yet limit the ACPI lookup to dock device IDs). If the ACPI object parsing is wrong, or if a system unrelated to docks happens to expose a \_SB.AMAC or \MACA object with data that passes the length/format check, the driver could pick up an unintended MAC address on any I225/I226 NIC, including onboard ones. That would show up as a network interface with a wrong MAC address, causing it to be unreachable at its expected address orto collide with another device on the network. The ACPI object parsing itself (string length checks, hex2bin conversion) is also new code in the probe path; a bug there could misparse a valid ACPI buffer and either wrongly reject a valid dock MAC (falling back to the old NVM path, low risk) or wrongly accept malformed data as a MAC (higher risk, described above). To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2165864/+subscriptions
[Bug 2170270] [NEW] Xen Dom0 fails to boot with "nvme.poll_queues=24" and "dom0_max_vcpus=6 dom0_vcpus_pin"
Public bug reported: Real human writing: #### Problem: Booting Xen hypervisor with Linux Dom0. GRUB loads, Xen kernel messages load up to "Using 6 CPU" # From this point: Next screen goes black and stays blank for 10+minutes. Have to force reboot and choose non XEN kernel booting option via GRUB. # From this point expected behaviour without bug: Next screen goes black and stays so for 30-70sec and Dom0 kernel messages appear, Next login is possible and system is running, "xl info" and other xl commands function. #### Cause: I spent 2 days rebooting to narrow this down.. This happens if we set both settings same time: NVME io polling and XEN kernel CPU limits, via default grub configs: GRUB_CMDLINE_LINUX_DEFAULT="nvme.poll_queues=24" # Can also be set via /mnt/oldroot/etc/modprobe.d/nvme.conf # For proper polling setup nvme.io_poll=1 should also be set, # but symptom already appears if we set only nvme.poll_queues=24 and GRUB_CMDLINE_XEN_DEFAULT="dom0_max_vcpus=6 dom0_vcpus_pin" #### Affected software: 24.04.4 LTS (Noble Numbat) Kernel: 6.8.0-136-generic x86_64 And HWE: 7.0.0-38-generic x86_64 xen-hypervisor-4.17-amd64 4.17.3+10-g091466ba55-1.1ubuntu3 ## updating was attempted, but same symptoms still: 26.04.1 LTS (Resolute Raccoon) Kernel: 7.0.0-38-generic x86_64 xen-hypervisor-4.20-amd64 4.20.2+7-g1badcf5035-2build2 #### Hardware: Supermicro MB, AMD EPYC Zen5 CPU with 48threads, (horrendeus 2+min boot time to GRUB, server MB with BMC/IPMI) BIOS (not sure how relevant): ACPI SRAT L3 Cache As NUMA Domain - Enabled IOMMU - enabled DMA Protection - enabled DMAr Support - disabled (if enabled we get +50sec to boot time) DRTM Virtual Device Support - enabeld DRTM Memory Reservation - enabeld SEV-SNP Support - enabled ASPM Support - enabled for 24.04 testing later set it to disabled for 26.04 testing. Gen5 NVME disks connected via bifurcation cards: 5pieces: Crucial T700 / PN: CT2000T700SSD5 4pieces: FireCuda 540 / PN: 3JT301-300 1piece: Lexar NM1090 / PN: LNM1090002T-RNANG Sadly not my personal system, so I can not do further heavy testing on it. io polling does give very good performance boost to Gen5 NVME, and even Gen4. Sad we cant use it, as CPU pinning is more important for XEN hypervizor system. ** Affects: linux (Ubuntu) Importance: Undecided Status: New ** Tags: kernel-bug nvme xen -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2170270 Title: Xen Dom0 fails to boot with "nvme.poll_queues=24" and "dom0_max_vcpus=6 dom0_vcpus_pin" Status in linux package in Ubuntu: New Bug description: Real human writing: #### Problem: Booting Xen hypervisor with Linux Dom0. GRUB loads, Xen kernel messages load up to "Using 6 CPU" # From this point: Next screen goes black and stays blank for 10+minutes. Have to force reboot and choose non XEN kernel booting option via GRUB. # From this point expected behaviour without bug: Next screen goes black and stays so for 30-70sec and Dom0 kernel messages appear, Next login is possible and system is running, "xl info" and other xl commands function. #### Cause: I spent 2 days rebooting to narrow this down.. This happens if we set both settings same time: NVME io polling and XEN kernel CPU limits, via default grub configs: GRUB_CMDLINE_LINUX_DEFAULT="nvme.poll_queues=24" # Can also be set via /mnt/oldroot/etc/modprobe.d/nvme.conf # For proper polling setup nvme.io_poll=1 should also be set, # but symptom already appears if we set only nvme.poll_queues=24 and GRUB_CMDLINE_XEN_DEFAULT="dom0_max_vcpus=6 dom0_vcpus_pin" #### Affected software: 24.04.4 LTS (Noble Numbat) Kernel: 6.8.0-136-generic x86_64 And HWE: 7.0.0-38-generic x86_64 xen-hypervisor-4.17-amd64 4.17.3+10-g091466ba55-1.1ubuntu3 ## updating was attempted, but same symptoms still: 26.04.1 LTS (Resolute Raccoon) Kernel: 7.0.0-38-generic x86_64 xen-hypervisor-4.20-amd64 4.20.2+7-g1badcf5035-2build2 #### Hardware: Supermicro MB, AMD EPYC Zen5 CPU with 48threads, (horrendeus 2+min boot time to GRUB, server MB with BMC/IPMI) BIOS (not sure how relevant): ACPI SRAT L3 Cache As NUMA Domain - Enabled IOMMU - enabled DMA Protection - enabled DMAr Support - disabled (if enabled we get +50sec to boot time) DRTM Virtual Device Support - enabeld DRTM Memory Reservation - enabeld SEV-SNP Support - enabled ASPM Support - enabled for 24.04 testing later set it to disabled for 26.04 testing. Gen5 NVME disks connected via bifurcation cards: 5pieces: Crucial T700 / PN: CT2000T700SSD5 4pieces: FireCuda 540 / PN: 3JT301-300 1piece: Lexar NM1090 / PN: LNM1090002T-RNANG Sadly not my personal system, so I can not do further heavy testing on it. io polling does give very good performance boost to Gen5 NVME, and even Gen4. Sad we cant use it, as CPU pinning is more important for XEN hypervizor system. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2170270/+subscriptions
[Bug 2169926] Re: Failed to Boot After GRUB
** Tags added: kernel-daily-bug -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2169926 Title: Failed to Boot After GRUB Status in linux package in Ubuntu: New Bug description: My laptop updated its kernel today from 7.0.0-34-Generic to 7.0.0-38-Generic. First time booting after update, I go to the GRUB menu and select Ubuntu. My screen went black. It was supposed to go to the password screen to unlock my hard drive. My laptop will boot after either going back to the 7.0.0-34-Generic kernel, or booting with "nomodeset" option. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-38-generic 7.0.0-38.38 ProcVersionSignature: Ubuntu 7.0.0-38.38-generic 7.0.14 Uname: Linux 7.0.0-38-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: dcfau6 4302 F.... pipewire dcfau6 4323 F.... wireplumber /dev/snd/pcmC0D0p: dcfau6 4302 F...m pipewire /dev/snd/seq: dcfau6 4302 F.... pipewire CasperMD5CheckResult: pass CurrentDesktop: KDE Date: Wed Oct 7 23:45:51 2026 InstallationDate: Installed on 2026-04-24 (166 days ago) InstallationMedia: Ubuntu-Studio 26.04 "Resolute Raccoon" - Release amd64 (20260423.1) Lsusb: Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 003 Device 002: ID 04f2:b872 Chicony Electronics Co., Ltd HP 5MP Camera Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub MachineType: HP HP OmniBook 7 Laptop 16-bh0xxx ProcFB: 0 simpledrmdrmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-7.0.0-38-generic root=/dev/mapper/ubuntu--vg-ubuntu--lv ro quiet splash preempt=full threadirqs rcu_nocbs=all nomodeset PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon. SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 04/16/2026 dmi.bios.release: 15.12 dmi.bios.vendor: AMI dmi.bios.version: F.12 dmi.board.asset.tag: Base Board Asset Tag dmi.board.name: 8E60 dmi.board.vendor: HP dmi.board.version: 55.42 dmi.chassis.type: 10 dmi.chassis.vendor: HP dmi.chassis.version: Chassis Version dmi.ec.firmware.release: 55.42 dmi.modalias: dmi:bvnAMI:bvrF.12:bd04/16/2026:br15.12:efr55.42:svnHP:pnHPOmniBook7Laptop16-bh0xxx:pvr:rvnHP:rn8E60:rvr55.42:cvnHP:ct10:cvrChassisVersion:skuD2KR6UA#ABA:pfa103C_5335M8HPOmniBook7: dmi.product.family: 103C_5335M8 HP OmniBook 7 dmi.product.name: HP OmniBook 7 Laptop 16-bh0xxx dmi.product.sku: D2KR6UA#ABA dmi.sys.vendor: HP To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2169926/+subscriptions
[Bug 2169960] Re: [i915][CFL] Color inversion on resume/boot with 10-bit primary plane (Sharp 0x149a eDP)
** Tags added: kernel-daily-bug -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2169960 Title: [i915][CFL] Color inversion on resume/boot with 10-bit primary plane (Sharp 0x149a eDP) Status in linux package in Ubuntu: New Bug description: 1) The release of Ubuntu you are using: Ubuntu 26.04 LTS 2) The version of the package you are using: linux-image-7.0.0-38-generic 3) What you expected to happen: The i915 driver should correctly apply hardware dithering when a 10-bit plane is requested by Mutter on an 8-bit eDP panel. It must also properly restore the hardware Gamma LUT and display pipe state upon waking from ACPI sleep states (both s2idle and S3), displaying normal colors. 4) What happened instead: Upon cold boot and after resuming from sleep, the screen colors are completely inverted or heavily posterized. --- DETAILED ROOT CAUSE & HARDWARE SPECS: * Machine: Dell Precision 5530 * CPU/GPU: Intel Core i7-8850H (Coffee Lake 3e9b) / Intel UHD 630 * Panel: Internal 1080p eDP panel (Sharp 0x149a) * Compositor: GNOME on Wayland (Mutter 50.1) Taking a screenshot (PrtScr) while the screen is physically inverted yields a PERFECT image with normal colors. This isolates the issue to the kernel i915 driver failing to push the correct state to the hardware/panel, while the Wayland compositor renders correctly. Running `drm_info` reveals that Mutter is successfully requesting and scanning out a 10-bit primary plane: Format: XRGB2101010 (0x30335258) The Sharp 1080p panel is an 8-bit (or 6-bit+FRC) display. The i915 driver accepts the 10-bit commit from Mutter but silently fails to configure the pipe's hardware dithering or color space conversion correctly on boot and resume, causing a severe bit-shift that manifests as color inversion. Workarounds tested that failed to persist: - i915.enable_dc=0 and i915.enable_psr=0 (Did not prevent the bug). - mem_sleep_default=deep (Entered S3 successfully, but inversion still happened on wake). - Restricting the connector via `video=eDP-1:bpc=8` in GRUB temporarily forces Mutter to XRGB8888, but the driver state still desyncs across power cycles. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-38-generic 7.0.0-38.38 ProcVersionSignature: Ubuntu 7.0.0-38.38-generic 7.0.14 Uname: Linux 7.0.0-38-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: omar-ashraf 5735 F.... wireplumber /dev/snd/seq: omar-ashraf 5715 F.... pipewire CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Thu Oct 8 12:54:25 2026 InstallationDate: Installed on 2026-04-09 (182 days ago) InstallationMedia: Ubuntu 24.04.3 LTS "Noble Numbat" - Release amd64 (20250805.1) Lsusb: Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 003: ID 27c6:5395 Shenzhen Goodix Technology Co.,Ltd. Fingerprint Reader Bus 001 Device 004: ID 0c45:671d Microdia Integrated_Webcam_HD Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub MachineType: Dell Inc. Precision 5530 ProcEnviron: LANG=en_US.UTF-8 PATH=(custom, no user) SHELL=/bin/bash TERM=xterm-256color XDG_RUNTIME_DIR=<set> ProcFB: 0 i915drmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-38-generic root=UUID=f4aac615-68a0-4be5-b90f-363df54a8e8f ro video=eDP-1:bpc=8 mem_sleep_default=deep i915.enable_dc=0 quiet splash i915.enable_psr=0 i915.enable_psr=0 i915.enable_fbc=0 crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M SourcePackage: linux UpgradeStatus: Upgraded to resolute on 2026-10-02 (6 days ago) dmi.bios.date: 12/11/2024 dmi.bios.release: 1.42 dmi.bios.vendor: Dell Inc. dmi.bios.version: 1.42.0 dmi.board.name: 0NFGCT dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.asset.tag: AI942495 dmi.chassis.type: 10 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvr1.42.0:bd12/11/2024:br1.42:svnDellInc.:pnPrecision5530:pvr:rvnDellInc.:rn0NFGCT:rvrA00:cvnDellInc.:ct10:cvr:sku087D:pfaPrecision: dmi.product.family: Precision dmi.product.name: Precision 5530 dmi.product.sku: 087D dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2169960/+subscriptions