Public bug reported: Ubuntu 26.04.1 LTS, kernel 7.0.0-31-generic (package 7.0.0-31.31). Hardware: Lenovo ThinkPad T14 Gen 2a, product 20XLS14Y00. Current BIOS: R1MET65W (1.35), EC R1MHT65W. Suspend mode: s2idle. IOMMU default domain: Translated.
Problem: Waking from suspend feels like roughly 30 seconds before the lock/login screen appears. Examination of four recorded suspend/resume cycles found a repeatable ~10.26-second stall inside kernel resume. This accounts for part of the perceived delay; the full 30 seconds has not been instrumented. The stall was observed with BIOS 1.33 and persists with BIOS 1.35. Evidence: Using the kernel's _SOURCE_MONOTONIC_TIMESTAMP from journalctl JSON, the most recent recorded cycle in the examined boot has: 92.332175: ACPI: EC: interrupt unblocked 102.592656: clocksource: Long readout interval, skipping watchdog check 102.607541: USB resume messages begin 102.608959: AMDGPU resume messages begin 102.615186: NVMe resume messages begin 103.136892: PM: suspend exit Three preceding cycles similarly show gaps of approximately 10.256, 10.265, and 10.261 seconds at the same point in resume. These are wake-time gaps, excluding the interval spent suspended. The kernel module amd-pmc.ko.zst contains a DMI entry for 20XK but no 20XL entry. No "Using s2idle quirk" message appears during boot. amd_pmc is loaded and bound; disable_workarounds is N. Likely cause / upstream fix: Commit e25fb2258bddbcf70df69d1358be3e1274bdc5f2: "platform/x86/amd/pmc: Add T14 Gen2 AMD (20XL) to s2idle quirk list" https://lists.openwall.net/linux-kernel/2026/07/17/358 The upstream report describes the same missing model match and ~10.25s firmware SMI stall on NVMe D3->D0 with IOMMU translation enabled. The fix adds the 20XL DMI match to the existing workaround. Please consider backporting this fix to the Ubuntu 26.04 GA kernel. Expected: Resume promptly to the lock screen. Actual: Repeated ~10.26s kernel stall before devices and desktop resume. Mainline testing: I have not yet tested a kernel containing the fix on this machine. Reproduction: Suspend using the desktop or by closing the lid, then wake the machine. Record the method used, suspend duration, dock/peripheral state, and measured wake-to-lock-screen delay in additional testing. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-31-generic 7.0.0-31.31 ProcVersionSignature: Ubuntu 7.0.0-31.31-generic 7.0.14 Uname: Linux 7.0.0-31-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Wed Sep 16 11:19:40 2026 InstallationDate: Installed on 2026-04-29 (141 days ago) InstallationMedia: Ubuntu 26.04 "Resolute Raccoon" - Release amd64 (20260423.1) MachineType: LENOVO 20XLS14Y00 ProcFB: 0 amdgpudrmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-7.0.0-31-generic root=/dev/mapper/ubuntu--vg-ubuntu--lv ro quiet splash crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M SourcePackage: linux Title: ThinkPad T14 Gen 2 AMD (20XL): ~10.26s s2idle resume stall; missing upstream AMD PMC quirk UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 08/07/2026 dmi.bios.release: 1.35 dmi.bios.vendor: LENOVO dmi.bios.version: R1MET65W (1.35 ) dmi.board.asset.tag: Not Available dmi.board.name: 20XLS14Y00 dmi.board.vendor: LENOVO dmi.board.version: SDK0J40697 WIN dmi.chassis.asset.tag: AI778595 dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: None dmi.ec.firmware.release: 1.35 dmi.modalias: dmi:bvnLENOVO:bvrR1MET65W(1.35):bd08/07/2026:br1.35:efr1.35:svnLENOVO:pn20XLS14Y00:pvrThinkPadT14Gen2a:rvnLENOVO:rn20XLS14Y00:rvrSDK0J40697WIN:cvnLENOVO:ct10:cvrNone:skuLENOVO_MT_20XL_BU_Think_FM_ThinkPadT14Gen2a:pfaThinkPadT14Gen2a: dmi.product.family: ThinkPad T14 Gen 2a dmi.product.name: 20XLS14Y00 dmi.product.sku: LENOVO_MT_20XL_BU_Think_FM_ThinkPad T14 Gen 2a dmi.product.version: ThinkPad T14 Gen 2a dmi.sys.vendor: LENOVO ** Affects: linux (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug resolute resume suspend wayland-session -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2167524 Title: ThinkPad T14 Gen 2 AMD (20XL): ~10.26s s2idle resume stall; missing upstream AMD PMC quirk To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2167524/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
