Public bug reported: On an ASUS Zenbook A14 UX3407QA (Qualcomm Snapdragon X1P42100, aarch64), the PCIe6a QMP PHY fails to initialise on roughly 70% of boots. When it fails, the PCIe host bridge does not probe, so the on-board Qualcomm WCN6855 / QCNFA765 Wi-Fi adapter never enumerates and no wireless interface exists at all. The only known remedy is to reboot repeatedly until the PHY happens to train.
This is **intermittent and not kernel-version-specific**, which distinguishes it from a regression and suggests a race or an incomplete power-up sequence rather than a recent change. ### Error signature (from a failing boot) ``` qcom-qmp-pcie-phy 1c0e000.phy: phy initialization timed-out phy phy-1c0e000.phy.4: phy poweron failed --> -110 qcom-pcie 1c08000.pci: error -ETIMEDOUT: cannot initialize host qcom-pcie 1c08000.pci: probe with driver qcom-pcie failed with error -110 ``` On a succeeding boot, the identical configuration instead yields: ``` qcom-pcie 1c08000.pci: PCIe Gen.3 x1 link up ath11k_pci 0004:01:00.0: wcn6855 hw2.1 ``` ### Frequency, measured over 24 consecutive boots | Kernel | Boots | PHY OK | Success rate | |---|---|---|---| | 7.0.0-14-generic | 10 | 3 | 30% | | 7.0.0-28-generic | 14 | 4 | 29% | | **Total** | **24** | **7** | **29%** | Both packaged kernels fail at statistically indistinguishable rates. ### Environment - Ubuntu 26.04 LTS (aarch64) - Kernel `7.0.0-28-generic`, `Ubuntu 7.0.0-28.28-generic 7.0.12` - Also reproduced on `7.0.0-14-generic` - Device tree model: `ASUS Zenbook A14 (UX3407QA)` - Compatible: `asus,zenbook-a14-ux3407qa-oled asus,zenbook-a14-ux3407qa qcom,x1p42100` - BIOS: Insyde `UX3407QA.315` (2026-03-26) - Affected PHY: `/soc@0/phy@1c0e000`, compatible `qcom,x1e80100-qmp-gen3x2-pcie-phy` - Affected controller: `/soc@0/pci@1c08000`, compatible `qcom,pcie-x1e80100` - Wi-Fi: `17cb:1103` WCN6855 (QCNFA765), driver `ath11k_pci` ### Steps to reproduce 1. Boot the machine. 2. `lspci | grep -i network` 3. On ~70% of boots there is no network device, and `journalctl -k -b 0 | grep 1c0e000` shows `phy initialization timed-out`. 4. Reboot and repeat — it succeeds roughly 1 boot in 3. ### What has been ruled out - **Not a kernel regression.** Reproduced at ~30% success on both `7.0.0-14` and `7.0.0-28`. - **Not cold-vs-warm boot state.** Full cold power-offs (complete shutdown, ~10 s off) fail at the same rate, so it is not simply firmware handing over a powered-down PHY that a warm reboot then inherits. - **Not a missing driver or firmware.** `ath11k`/`ath11k_pci` and `/lib/firmware/ath11k/WCN6855/` are present. On boots where the PHY does train, the adapter enumerates and works normally. - **Not rfkill, and not dead silicon.** Bluetooth on the same WCN6855 combo chip works on **every** boot, including failing ones — so the chip has power; only its PCIe side fails. - **Not a device-tree modification.** Stock Ubuntu DTB, verified byte-identical to the shipped file. `wifi@0` and `phy@1c0e000` are both `status = "okay"`. - **No log difference.** Comparing a succeeding and a failing boot around PHY init shows identical ordering and identical messages (same devlink dependency-cycle notices, same `supply vdda not found, using dummy regulator` warnings, same controller retry blocks) right up to the point one trains and the other times out. ### Note on the existing upstream fix This looks related to the known "PHY powered down by boot firmware" failure mode addressed by: > phy: qcom: qmp-pcie: Fix PHY initialization when powered down by firmware > https://lkml.org/lkml/2025/8/14/738 (Aug 2025) Since this kernel is based on upstream 7.0.12, that patch should already be included — so the fix appears **incomplete for x1p42100**, or a second failure path exists. Worth noting that X1P42100 PCIe support depends on the NOCSR PCIe PHY reset series (https://patchew.org/linux/[email protected]/). ### Impact No wireless networking on ~70% of boots on a retail laptop. Users must reboot repeatedly, which is especially poor on a machine with no built-in Ethernet port. ### Additional note (separate issue, not part of this report) This model also needs an `ath11k` `board-2.bin` entry for calibration variant `UX3407Q` (`subsystem-device=950a, qmi-chip-id=18, qmi-board-id=255`), absent from `linux-firmware`. Without it `ath11k` fails with `qmi failed to fetch board file: -2` even when PCIe does come up. Notably, all six existing ASUS (`subsystem-vendor=14cd`) `qmi-chip-id=18` blobs in `board-2.bin` are byte-identical, so adding the missing name mapped to that same data is sufficient. That is arguably a `linux-firmware` bug and should be filed separately. --- ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-28-generic 7.0.0-28.28 ProcVersionSignature: Ubuntu 7.0.0-28.28-generic 7.0.12 Uname: Linux 7.0.0-28-generic aarch64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: arm64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: lance-burger 3455 F.... pipewire lance-burger 3814 F.... wireplumber /dev/snd/seq: lance-burger 3455 F.... pipewire CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Mon Jul 27 23:55:08 2026 InstallationDate: Installed on 2026-07-24 (3 days ago) InstallationMedia: Ubuntu 26.04 "Resolute Raccoon" - Release arm64 (20260423.1) Lspci-vt: -[0006:00]---00.0-[01-ff]----00.0 Micron Technology Inc 2500 NVMe SSD (DRAM-less) MachineType: ASUSTeK COMPUTER INC. ASUS Zenbook A14 UX3407QA_UX3407QA ProcEnviron: LANG=en_US.UTF-8 PATH=(custom, no user) SHELL=/bin/bash TERM=xterm-256color XDG_RUNTIME_DIR=<set> ProcFB: 0 msmdrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-28-generic root=UUID=2c4529d9-be58-40f3-a6aa-9c9d8f72cf99 ro clk_ignore_unused pd_ignore_unused cma=128M efi=noruntime quiet splash console=tty0 crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon. RfKill: 0: hci0: Bluetooth Soft blocked: no Hard blocked: no SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) acpidump: dmi.bios.date: 03/26/2026 dmi.bios.release: 3.21 dmi.bios.vendor: Insyde dmi.bios.version: UX3407QA.315 dmi.board.asset.tag: ATN12345678901234567 dmi.board.name: UX3407QA dmi.board.vendor: ASUSTeK COMPUTER INC. dmi.board.version: 1.0 dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: ASUSTeK COMPUTER INC. dmi.chassis.version: 1.0 dmi.ec.firmware.release: 3.14 dmi.modalias: dmi:bvnInsyde:bvrUX3407QA.315:bd03/26/2026:br3.21:efr3.14:svnASUSTeKCOMPUTERINC.:pnASUSZenbookA14UX3407QA_UX3407QA:pvr1.0:rvnASUSTeKCOMPUTERINC.:rnUX3407QA:rvr1.0:cvnASUSTeKCOMPUTERINC.:ct10:cvr1.0:sku:pfaASUSZenbookA14: dmi.product.family: ASUS Zenbook A14 dmi.product.name: ASUS Zenbook A14 UX3407QA_UX3407QA dmi.product.version: 1.0 dmi.sys.vendor: ASUSTeK COMPUTER INC. ** Affects: linux (Ubuntu) Importance: Undecided Status: New ** Tags: apport-bug arm64 resolute wayland-session x1p42100 ** Attachment added: "Latest failure log report" https://bugs.launchpad.net/bugs/2161926/+attachment/5987124/+files/phy-failure-logs.txt -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2161926 Title: qcom-qmp-pcie-phy 1c0e000.phy intermittently fails to initialise on x1p42100 (ASUS Zenbook A14 UX3407QA), leaving WCN6855 Wi-Fi unusable on ~70% of boots To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2161926/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
