Public bug reported: Title: ath12k_wifi7 WCN785x drops traffic when firmware assigns peer_id 0
Description: Ubuntu release: Ubuntu 26.04.1 LTS Kernel package: linux-image-7.0.0-31-generic 7.0.0-31.31 Kernel signature: Ubuntu 7.0.0-31.31-generic 7.0.14 Hardware: - Qualcomm WCN785x Wi-Fi 7 / FastConnect 7800 [17cb:1107], revision 01 - Foxconn subsystem [105b:e0f7] - Driver: ath12k_wifi7_pci Firmware: - fw_version 0x1103006c - build timestamp 2026-03-06 09:10 - WLAN.HMT.1.1.c7-00108-QCAHMTSWPL_V1.0_V2.0_SILICONZ_UPSTREAM-3 - linux-firmware-qualcomm-wireless 20260319.git217ca6e4-0ubuntu1.2 Summary: When this adapter is associated with a 5 GHz access point and firmware assigns peer_id 0, the interface remains associated but traffic is dropped. New connections time out and applications report that they are offline. The kernel repeatedly logs: ath12k_wifi7_pci 0000:0c:00.0: dp_tx: failed to find the peer with peer_id 0 I observed 198 instances between 11:14:57 and 11:18:00 in one boot. At 11:18:01 I disconnected from the 5 GHz BSSID and associated with the corresponding 2.4 GHz access point. The errors stopped immediately and connectivity resumed. Steps to reproduce: 1. Boot Ubuntu with the WCN785x adapter using ath12k_wifi7_pci. 2. Associate with the affected 5 GHz access point. 3. Use the network until firmware assigns peer_id 0 and the connection stops passing traffic. 4. Check the kernel journal for "dp_tx: failed to find the peer with peer_id 0". 5. Disconnect and associate with the corresponding 2.4 GHz access point; traffic resumes and the errors stop. Actual result: Peer lookup fails for peer_id 0 and packets are dropped even though Wi- Fi remains associated. Expected result: peer_id 0 should be accepted as a valid firmware-assigned peer ID and traffic should continue normally. Upstream status: This appears to be the exact issue fixed by upstream patch "wifi: ath12k: allow peer_id 0 in dp peer lookup": https://lkml.iu.edu/2605.1/06622.html The patch description contains the identical TX error and was tested on WCN7850 hw2.0 with the same firmware build used here. It changes ath12k to reject only IDs greater than or equal to ATH12K_DP_PEER_ID_INVALID instead of also rejecting zero. The fix was included in the ath-next pull request for Linux 7.2: https://www.mail-archive.com/[email protected]/msg17769.html Please backport this fix to Ubuntu's 7.0 kernel series. Regression status: Unknown. The previously installed 7.0.0-30 kernel did not record this exact diagnostic, but its ath12k_wifi7 module has the same source version as 7.0.0-31. Therefore I cannot reliably claim that 7.0.0-31 introduced the driver defect. Current workaround: Prefer the corresponding 2.4 GHz network. Reassociation may temporarily help, but it is not reliable because firmware can assign peer_id 0 again. 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 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC2: aimama 7464 F.... wireplumber /dev/snd/controlC0: aimama 7464 F.... wireplumber /dev/snd/controlC1: aimama 7464 F.... wireplumber /dev/snd/seq: aimama 7385 F.... pipewire CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Mon Sep 21 11:38:28 2026 InstallationDate: Installed on 2026-06-11 (102 days ago) InstallationMedia: Ubuntu 26.04 "Resolute Raccoon" - Release amd64 (20260423.1) MachineType: Micro-Star International Co., Ltd. MS-7E56 ProcFB: 0 nvidia-drmdrmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-7.0.0-31-generic root=UUID=a11e2bc8-0109-4e17-95bf-66a3a3cbc8bc ro rootflags=subvol=@ rootflags=subvol=@ 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: 06/25/2026 dmi.bios.release: 5.41 dmi.bios.vendor: American Megatrends International, LLC. dmi.bios.version: 1.AA2 dmi.board.asset.tag: To be filled by O.E.M. dmi.board.name: B850 GAMING PLUS WIFI (MS-7E56) dmi.board.vendor: Micro-Star International Co., Ltd. dmi.board.version: 1.0 dmi.chassis.asset.tag: To be filled by O.E.M. dmi.chassis.type: 3 dmi.chassis.vendor: Micro-Star International Co., Ltd. dmi.chassis.version: 1.0 dmi.modalias: dmi:bvnAmericanMegatrendsInternational,LLC.:bvr1.AA2:bd06/25/2026:br5.41:svnMicro-StarInternationalCo.,Ltd.:pnMS-7E56:pvr1.0:rvnMicro-StarInternationalCo.,Ltd.:rnB850GAMINGPLUSWIFI(MS-7E56):rvr1.0:cvnMicro-StarInternationalCo.,Ltd.:ct3:cvr1.0:skuTobefilledbyO.E.M.:pfaTobefilledbyO.E.M.: dmi.product.family: To be filled by O.E.M. dmi.product.name: MS-7E56 dmi.product.sku: To be filled by O.E.M. dmi.product.version: 1.0 dmi.sys.vendor: Micro-Star International Co., Ltd. ** Affects: linux (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug resolute 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/2167833 Title: ath12k_wifi7 WCN785x drops traffic when firmware assigns peer_id 0 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2167833/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
