From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AD38C606A7C1 for ; Wed, 4 Nov 2026 15:19:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=XLAvil/H DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Unsubscribe-Post: List-Owner; bh=bLOJZaXgrljjby6d2ZZG7h7GGo4k7OpcvIB3L0adEqA=; b=XLAvil/HfV56eY tlfMukmXxs6p+0vK9cxaxe+EdLaj6brYwqNAqkw5W1aMRNBHiaZBZTBJTaVJFXO8HBzVnsOCahIS4 gRgt57WoJKagYy1iAJ3gfb6mAugVABW2WemSA/Tm7X5NUxZktCXcWgDyagCQcRVHb7p/V2qizHYHg Rb9NFYQvYzv7diJWtZ9AccMrIKZQ6UgE8XE8HI0lpY6Kiikli4ZCofX+Y+klh7zjupciNQWzq3BXL XIqLebdVBeNLfqhuzCzm2EJgjh+f4k/EEZUnDyGc5Zouxm7eGNiK8RNitU0nu2FRL4D8hnAQ9uyXs h+HMXGAYpWI+pbe7Ctdw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xOcm1-00000005kwz-3gAX; Wed, 04 Nov 2026 15:19:37 +0000 Received: from mail-wr1-f42.google.com ([209.85.221.42]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xOclz-00000005kv8-00QR for linux-arm-kernel@lists.infradead.org; Wed, 04 Nov 2026 15:19:36 +0000 Received: by mail-wr1-f42.google.com with SMTP id ffacd0b85a97d-48b001cd92bso393033f8f.2 for ; Wed, 04 Nov 2026 07:19:34 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1793805573; x=1794410373; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=bLOJZaXgrljjby6d2ZZG7h7GGo4k7OpcvIB3L0adEqA=; b=spLhq8vj/Cmkrc2Rn52GNrr8Qke+eTMQWSmCIdruuwAdAC5hnGkhD6KAI6chuNNqve tTcTznQSjeUe90sPzssyo+ZkAWCCvffnxAoNrV0OwuDm47y4xh4U4xY94PNstM9fteXz uqVfdnvuJLDen2CWeoK6DQzxCCg5FUjx5jxZDI5BvVWlhREb715BFHxudCXx8eKOLe7k xXRXKJL4fjS+7y8tMADBDtwR+yOch6rL0ff3s1qJXz1o9iODD+L6lcHez5jeuvcvCU1z cR7T6VYn3JoVGgEY+GVKFbSVC3z1ZwQZJLS6SL2qUjh1uWlkfnVAz2qhGQFwPIIi83HG mCCQ== X-Forwarded-Encrypted: i=1; AKwUvBzY0y5VPfwmT+xJWRiOiYzPw5Ay7W/6Tjl7qt0fzj0OQa6/1sGgAs8m/qHsTlLAH4MQbxfF76VKr0FqwrI7ryUB@lists.infradead.org X-Gm-Message-State: APuU4Z9/41KtLU7pIjm/bsopdM2PBSWCJ5SB+N3CQJBcIqMX9lAmyRmN pw9zYx/nm48Upts5gsfOGQzLJ3Vzv/JhdB490LBqzp6o0lTN1lAlDCtUiCXB4/fCkFVM5dIXxHR WrDQMM9oS3cIs X-Gm-Gg: AYBFou089yOG2Hehk9nwIW422eioNNZSfYTHvRtFUCDqSKZXZN/Uc+UGQUfT19QnXVF RTU/NEfkVJUx37D0NaiyY1PHxI17UICWcUsQaxWpJQ+jRSNg+PBXtu24ZnRB6AS9tl4Zj7XNjwY 91W+6IOunqzZxV3zw81wPRa6eP7ko4VwVrfEzaZaAGSn5+yJHsdiydVYQoxr/6d/FPwW4imXHI+ OEQOiGm4/Rkn76i1G5S8lTxEAMWYaPLeCULBiFUdYneda4/IXUA1u7lhf8hwP+1gFoqWLRv0FGp nZet8b2rIXajhsQa5xuupX47nfCAUFaBcY3Lf0sMXvXFRuYwD47vus2qBMa+oS+0RqXoiZlNMat CKw4JjSXjzypCotSURwwlfXqgE3GKnTqGaFzs4x61LR8C3ga7td8STbLm87UabkUmwYEjT/F2EF odMqYHng0gVJ/6a7Ka7T2syleDRP5hT0Sti/SLe/Pq5VRJTsIEGMQZvG2/B/ZmAmvOV7vV4UxT+ K5wq38fdOQLOQmjWy2Hs4r/UvdzoyJxd74nxtp5Nj2RQb2U2DfWcIPY6IP4N12ga6k5ttZ0nba/ okzxF9s0/yvyGV9B5iGyxCOihVVUU00C17J3QfpJWCtzPWI= X-Received: by 2002:a5d:6950:0:b0:48e:3bc4:a367 with SMTP id ffacd0b85a97d-48e6e2fab84mr28602707f8f.33.1793805573103; Wed, 04 Nov 2026 07:19:33 -0800 (PST) Received: from lake ([2a02:810d:d09:1b65:4366:70cb:bf82:f8ac]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-48fec8d8e29sm4639812f8f.19.2026.11.04.07.19.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Nov 2026 07:19:31 -0800 (PST) From: Christian Schmidbauer To: netdev@vger.kernel.org Cc: maxime.chevallier@bootlin.com, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@kernel.org, kuba@kernel.org, pabeni@redhat.com, Oleksij Rempel , Christian Schmidbauer , stable@vger.kernel.org, Maxime Coquelin , Alexandre Torgue , Giuseppe Cavallaro , linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH net v2 3/3] net: stmmac: dwmac1000: stop hardware from dropping checksum-error packets Date: Wed, 4 Nov 2026 16:19:13 +0100 Message-ID: <20261104151914.2651241-4-opensource@grische.xyz> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20261104151914.2651241-1-opensource@grische.xyz> References: <20261104151914.2651241-1-opensource@grische.xyz> X-Archived-By: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261104_071935_083769_B01C9F9A X-CRM114-Status: GOOD ( 19.78 ) X-Spam-Score: -1.4 (-) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-21.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_EF,FROM_SUSPICIOUS_NTLD, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 When the checksum offload engine (CoE) is enabled, the dwmac1000 MAC silently drops any frame for which the engine detects a checksum error, before the driver sees it. This breaks VXLAN over IPv6 with zero UDP checksums, which RFC 6935 and RFC 6936 allow for tunnels. Set DMA_CONTROL_DT so that such frames are delivered instead of dropped, as commit fe4042797651 ("net: stmmac: dwmac4: stop hardware from dropping checksum-error packets") did for dwmac4. CoE remains enabled, so the driver still sees the error status and marks the skb CHECKSUM_NONE for the stack to verify. Set the bit only with enhanced descriptors. The normal descriptor parser does not report a checksum-only error to the stack, so cores that use it keep dropping such frames in hardware anyway. Tested on an Aruba AP-325 (ipq806x-gmac-dwmac) with Rx checksum offload on. Link: https://lore.kernel.org/all/20250625132117.1b3264e8@kernel.org/ Link: https://github.com/freifunk-gluon/gluon/issues/3783 Fixes: 47dd7a540b8a ("net: add support for STMicroelectronics Ethernet controllers.") Cc: # 6.6.x: ee0aace5f844: net: stmmac: Correctly handle Rx checksum offload errors Cc: # 6.6.x Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Christian Schmidbauer --- Depends on patches 1 and 2 of this series. v2: - Set DMA_CONTROL_DT only with enhanced descriptors. The normal descriptor parser does not report a checksum-only error, so cores with normal descriptors and Type 2 CoE keep the hardware drop. v1: https://lore.kernel.org/netdev/20261020190319.884375-1-opensource@grische.xyz/ drivers/net/ethernet/stmicro/stmmac/dwmac1000.h | 1 + drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c | 8 ++++++++ 2 files changed, 9 insertions(+) diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h b/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h index 1de1f929d61c..004e6e30a68b 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h @@ -163,6 +163,7 @@ enum rx_tx_priority_ratio { /* DMA operation mode defines (start/stop tx/rx are placed in common header)*/ /* Disable Drop TCP/IP csum error */ +#define DMA_CONTROL_DT 0x04000000 #define DMA_CONTROL_RSF 0x02000000 /* Receive Store and Forward */ #define DMA_CONTROL_DFF 0x01000000 /* Disaable flushing */ /* Threshold for Activating the FC */ diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c index 3ac7a7949529..31d5f79ef560 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c @@ -15,6 +15,7 @@ #include #include "dwmac1000.h" #include "dwmac_dma.h" +#include "stmmac.h" static void dwmac1000_dma_axi(void __iomem *ioaddr, struct stmmac_axi *axi) { @@ -129,6 +130,13 @@ static void dwmac1000_dma_operation_mode_rx(struct stmmac_priv *priv, { u32 csr6 = readl(ioaddr + DMA_CHAN_CONTROL(channel)); + /* Deliver checksum-error frames only with enhanced + * descriptors, because the normal descriptor parser does not + * report a checksum-only error. + */ + if (priv->plat->enh_desc) + csr6 |= DMA_CONTROL_DT; + if (mode == SF_DMA_MODE) { pr_debug("GMAC: enable RX store and forward mode\n"); csr6 |= DMA_CONTROL_RSF | DMA_CONTROL_DFF; -- 2.54.0