From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dl1-f43.google.com (mail-dl1-f43.google.com [74.125.82.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2ECED3F7869 for ; Wed, 6 May 2026 15:43:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.43 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778082189; cv=none; b=KF8CSOdFg8GEBvrwCtFCyNE96XBOrnIH4+lIo0uKAodvJeA4WbcEBqydMHWdB6i/lBxb4PGB8gGR2xLTlHJBG4Aw1oKsQXQmHGGssOm6VX1PNeD9vRNCwbrXOYhU1Aa0lTPWi5lTw/p8X3nyoMsRD9nt41/vnQJWgtNP5kmsOcM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778082189; c=relaxed/simple; bh=xsmzwdd1MBKsPgxT0f3M2DbdqDto8wvtJ7iL924KG3w=; h=Date:From:To:Subject:Message-ID:MIME-Version:Content-Type; b=RGi4HIS8hslpcsWYXi2kv+rZARre65VFHH1+1j4JvdvcTlRPptPCVkICsUuGjgFExuWu1lPm8K/Z0Ay/GEJdQ6+Lc5gOpDQVBu57y/+JlwAGNnWh+RDgSPlcbSsOwtR8qlEyOKwax7du7RPiMPSuNgVSq1KO02+eApZ/Sck4MuQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=networkplumber.org; spf=pass smtp.mailfrom=networkplumber.org; dkim=pass (2048-bit key) header.d=networkplumber-org.20251104.gappssmtp.com header.i=@networkplumber-org.20251104.gappssmtp.com header.b=S07HY8zE; arc=none smtp.client-ip=74.125.82.43 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=networkplumber.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=networkplumber.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=networkplumber-org.20251104.gappssmtp.com header.i=@networkplumber-org.20251104.gappssmtp.com header.b="S07HY8zE" Received: by mail-dl1-f43.google.com with SMTP id a92af1059eb24-12c8f9846c8so9097127c88.0 for ; Wed, 06 May 2026 08:43:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20251104.gappssmtp.com; s=20251104; t=1778082186; x=1778686986; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:subject:to:from :date:from:to:cc:subject:date:message-id:reply-to; bh=DVcF1pwCeCEpXjOB2ycJimgmvFvZxkVUxlvxYda7Z2E=; b=S07HY8zEm6Sadb19c/Bu3wx0hHVfcby8HPQ98m1Q7l1DI1OrVEjJp6OG0l9gwybvjY xeJQPqCW6qMlwaBFqdN5BNEOrK5OP5SdK8NIpJbHY7zFJfWjY6E7JuraRHKFsHYCgSuX d5P+g++MBLf+gCRIl/eCWteEt0+De7Vl0GHgPXIzQ7ROWFfXjL6EKxuvOI2bgD3CQFrK GVW15wAIjnlvj/F4Sip904J2/FZFh8oZuZwwSt/4nwETN0B0NhN509XAT478nW6DZZF/ xkAS1gDk74ZL5cjnjyyILjio3QBQwOK0oQmy9wEgbCXzReGtBFefI2/GEyaUAarpMQz7 81jg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778082186; x=1778686986; h=content-transfer-encoding:mime-version:message-id:subject:to:from :date:x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=DVcF1pwCeCEpXjOB2ycJimgmvFvZxkVUxlvxYda7Z2E=; b=KakvZDPYfSt1Mz8TLb1uy2cNq0nTIHeuz4eV89QqXbBKqH146xRFzXf3Hg/2dx+UsA LlPdxuTSjB51NcXhnsA+IFkB5FZFO8U1Qc4nnlWqOUr1QynvpDIP6Ki1mv631IWlJlqR YBQgwzIAAL/p6IpNa/E3e3ktVDruttAYiyq696XQwTKM7D7FSmY4bkjihKkY5dOK5Lqr 20u2ivHrgiPY0V2uLVty8D4aoRm6hhgCQM69OAdQUjuzX6Lc2CHtkfs2r9udjcQQHBA3 NLLwA6sr8lDGvhGAVRrpEFtEQwKYaMlAnfWa40RQcacl1Nw8z29ikgs/h+VJWIq3heI5 Emhw== X-Gm-Message-State: AOJu0YyRpVekCNkGO6mqUGdQGYs42B+E8f8uK/K51pl5gCDw1hHtSPKq tuKL3vdNCfPV41LQaoETS54aJB8l4NsfSqu0iDC7msgOp/I9jOUgce4FLcTzaRCm+rWIt/y4szE eFWli X-Gm-Gg: AeBDietlJpCYKGvpbvrSvQFZQ56DqGs76pFNX3iBLZjHNf8CR/ohLjTBuWVixaXUp2n aVZn98TnrOv67uk5Dt3j+3q1MLvRKdpjWn5eTgQejZjgKIe/PBeFHjJZhS7IgCx3zarqYJKqlKi blGF98mlshjhUhgWe6ZVT3Os8oA6UW6nkeOrKYQSXGlsfVcwGhqav08m0HPVMKcie5Q/ByxwnBG IYmOUnI0NWqPLMNDEduVbLcpN9ujuwSfuOo5rQTklylicem923taQNuPIaqQ9OWbIZNvD0ZTm8r OFO4l/I6krtPlLxmAwjscPlsKR668YNHUlHyRhKcwVilZJAFb4rAivSwQlh3KSU3ymzL1LxBxmm LpXu3s8JtQkGO1o5lYEELd9pIf0csca0zeA8D109uAZFxmdALr073njOpoaEQzEaDFHuG6QfrUi NAsywnbwuhXYiraqksZkgSHhoD4Ku7dA9gJj1PjlW8uY9aQg== X-Received: by 2002:a05:7022:6191:b0:12d:ca31:f1b4 with SMTP id a92af1059eb24-1318e92854fmr1995792c88.24.1778082185652; Wed, 06 May 2026 08:43:05 -0700 (PDT) Received: from phoenix.local ([104.202.41.210]) by smtp.gmail.com with ESMTPSA id a92af1059eb24-131f9679db9sm3757328c88.1.2026.05.06.08.43.05 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 06 May 2026 08:43:05 -0700 (PDT) Date: Wed, 6 May 2026 08:43:03 -0700 From: Stephen Hemminger To: netdev@vger.kernel.org Subject: Fw: [Bug 221470] New: ARP reply received at MAC level but neighbor entry not resolved (Linux 5.15, automotive BSP) for vlan interface Message-ID: <20260506084303.0fd0632b@phoenix.local> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Begin forwarded message: Date: Wed, 06 May 2026 05:29:26 +0000 From: bugzilla-daemon@kernel.org To: stephen@networkplumber.org Subject: [Bug 221470] New: ARP reply received at MAC level but neighbor ent= ry not resolved (Linux 5.15, automotive BSP) for vlan interface https://bugzilla.kernel.org/show_bug.cgi?id=3D221470 Bug ID: 221470 Summary: ARP reply received at MAC level but neighbor entry not resolved (Linux 5.15, automotive BSP) for vlan interface Product: Networking Version: 2.5 Hardware: ARM OS: Linux Status: NEW Severity: high Priority: P3 Component: IPV4 Assignee: stephen@networkplumber.org Reporter: rajkumar.veer@harman.com Regression: No Observed behavior: - During a system suspend=E2=80=93resume cycle, ARP requests are transmitted = successfully from the target. Corresponding ARP replies are continuously received at the EMAC/MAC level, as confirmed through driver debug logs and hardware RX statistics. However, the ARP entry is not being resolved in the kernel neighbor table (= ip neigh), resulting in failure of communication on a specific VLAN interface. This issue is sporadic and observed only on a particular VLAN interface. Recovery currently requires a full reboot of the system to restore proper A= RP functionality for particular vlan interface Environment: - Kernel version: Linux 5.15.x (vanilla, with automotive BSP integrations) Architecture: ARM64 & Exynosv920 soc Ethernet MAC driver: Sxgmac EMAC controller PHY: Macsec marvell phy/fixed phy switch =20 Network stack: mainline Linux networking stack What we verified: - ARP reply frame is valid and well formed. Destination MAC matches the interface MAC. No RX errors or CRC issues at the hardware level. ARP reply is visible via driver-level logging but not via tcpdump. Neighbor entry remains in INCOMPLETE state. Questions: - Are there any known issues in Linux 5.15 where ARP replies are dropped befo= re reaching the neighbor subsystem? Could RX offloading, VLAN filtering, checksum offload, or NAPI GRO/LRO affe= ct ARP processing in this scenario? Has anyone encountered similar issues on automotive BSPs or embedded Ethern= et MAC drivers? --=20 You may reply to this email to add a comment. You are receiving this mail because: You are the assignee for the bug.