From patchwork Sat Dec 16 19:36:53 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Linus Walleij X-Patchwork-Id: 13495719 X-Patchwork-Delegate: kuba@kernel.org Received: from mail-lf1-f50.google.com (mail-lf1-f50.google.com [209.85.167.50]) (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 73026328A6 for ; Sat, 16 Dec 2023 19:36:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linaro.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="sb/Pyfeh" Received: by mail-lf1-f50.google.com with SMTP id 2adb3069b0e04-50e270639d9so853540e87.3 for ; Sat, 16 Dec 2023 11:36:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1702755414; x=1703360214; darn=vger.kernel.org; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:from:to:cc:subject:date:message-id :reply-to; bh=9h9Ee/Vwe1BIQxBQqqcTxcTd1wrlWdnAiQYYrezMqwc=; b=sb/Pyfeh8z1OtZ04S5ISpAiwsUnCm7TTcqvL8zDF7U3cFLVgeUo57JXj00ycCB7YmX GnlFtZkYgkLf8zPffckB0xCZ38g7YgL6YoQ4NB0qZamEtZcYwOmHiFZmGxC+8PObXPz8 JKScbTCiJTQYconhPfHZcaJ2whRRxaTe8fcVbkrA7qZjQASsrhbc++br5LyyRDYpwqEh +N06bYd2lsnJQ9s3RLs5HoVTsvSLsA0sJFW2waXr6UOJoUa4To2XoeTXu8hJeWOEJFwy cDvW74uXXOqnGVzbMIytY0BMZMIHcRUnOPsjzpYmW+zivkFSSnR6qFw6okPYafWOBMjs r2KA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702755414; x=1703360214; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=9h9Ee/Vwe1BIQxBQqqcTxcTd1wrlWdnAiQYYrezMqwc=; b=STZl1bdm1MnUoDOrYHqe20hUusvo4/FkR7zgauL7FoZ1KB1ntzcIw5DXEC5VFNkHGn hAErKIWyJI5V1801+fcjgfWFs2Umm3a0lRDU82XTazh/EvmVlhuyOdgreLAXJRRtdcgD PFXbASBksqPtNv8r1LyL2mUvEIjLSPGs5XNbNfSkJ/xFHwNb4f9hr4QzTJXGwXtnnS6+ t0tPOFbhcedQt1fQHMwaTQzEP58cTo5fqZ4qOluG/0tJeb0CmgF7xhX4+pkJDTFEZeA5 svREEIq+oNTgMxETQHmIDEw9RlY+EKaebNYEAskuJ/cxauFnPfvLgrAuTRn0ycmiESFg a0dQ== X-Gm-Message-State: AOJu0YzU4jRIotkmNqZ4pk+uMmD/J7oVXpd+hjo5A3fgFzS+R7gp8tdU ZlZDMtzBpsvtEMMCJTe9yeRNlyONLA8iIh+xHzg= X-Google-Smtp-Source: AGHT+IFzz+T2hXXKxiCdBwJyMPL+OjikGaLBZmuS4blLXomqcUvu7YRY16pFw58HaKIwbEvjI8YB8w== X-Received: by 2002:a05:6512:693:b0:50b:b9c7:9f3d with SMTP id t19-20020a056512069300b0050bb9c79f3dmr9084665lfe.21.1702755414542; Sat, 16 Dec 2023 11:36:54 -0800 (PST) Received: from [127.0.1.1] ([85.235.12.238]) by smtp.gmail.com with ESMTPSA id u13-20020ac25bcd000000b0050bc96f5258sm2441553lfn.214.2023.12.16.11.36.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 16 Dec 2023 11:36:54 -0800 (PST) From: Linus Walleij Date: Sat, 16 Dec 2023 20:36:53 +0100 Subject: [PATCH net v2 2/2] net: ethernet: cortina: Bypass checksumming engine of alien ethertypes Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20231216-new-gemini-ethernet-regression-v2-2-64c269413dfa@linaro.org> References: <20231216-new-gemini-ethernet-regression-v2-0-64c269413dfa@linaro.org> In-Reply-To: <20231216-new-gemini-ethernet-regression-v2-0-64c269413dfa@linaro.org> To: Hans Ulli Kroll , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, Linus Walleij X-Mailer: b4 0.12.4 X-Patchwork-Delegate: kuba@kernel.org We had workarounds were the ethernet checksumming engine would be bypassed for larger frames, this fixed devices using DSA, but regressed devices where the ethernet was connected directly to a PHY. The devices with a PHY connected directly can't handle large frames either way, with or without bypass. Looking at the size of the frame is probably just wrong. Rework the workaround such that we just bypass the checksumming engine if the ethertype inside the actual frame is something else than 0x0800 (IPv4) or 0x86dd (IPv6). These are the only frames the checksumming engine can actually handle. VLAN framing (0x8100) also works fine. We can't inspect skb->protocol because DSA frames will sometimes have a custom ethertype despite skb->protocol is e.g. 0x0800. After this both devices with direct ethernet attached such as D-Link DNS-313 and devices with a DSA switch with a custom ethertype such as D-Link DIR-685 work fine. Fixes: d4d0c5b4d279 ("net: ethernet: cortina: Handle large frames") Signed-off-by: Linus Walleij --- drivers/net/ethernet/cortina/gemini.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/cortina/gemini.c b/drivers/net/ethernet/cortina/gemini.c index 6a7ea051391a..1400f19bf05b 100644 --- a/drivers/net/ethernet/cortina/gemini.c +++ b/drivers/net/ethernet/cortina/gemini.c @@ -1143,7 +1143,9 @@ static int gmac_map_tx_bufs(struct net_device *netdev, struct sk_buff *skb, skb_frag_t *skb_frag; dma_addr_t mapping; unsigned short mtu; + u16 ethertype; void *buffer; + __be16 *p; mtu = ETH_HLEN; mtu += netdev->mtu; @@ -1158,7 +1160,24 @@ static int gmac_map_tx_bufs(struct net_device *netdev, struct sk_buff *skb, word3 |= mtu; } - if (skb->ip_summed == CHECKSUM_PARTIAL) { + /* Dig out the the ethertype actually in the buffer and not what the + * protocol claims to be. This is the raw data that the checksumming + * offload engine will have to deal with. + */ + p = (__be16 *)(skb->data + 2 * ETH_ALEN); + ethertype = ntohs(*p); + if (ethertype == ETH_P_8021Q) { + p += 2; /* +2 sizeof(__be16) */ + ethertype = ntohs(*p); + } + + if (ethertype != ETH_P_IP && ethertype != ETH_P_IPV6) { + /* Hardware offloaded checksumming isn't working on non-IP frames. + * This happens for example on some DSA switches using a custom + * ethertype. Just bypass the engine for those. + */ + word1 |= TSS_BYPASS_BIT; + } else if (skb->ip_summed == CHECKSUM_PARTIAL) { int tcp = 0; /* We do not switch off the checksumming on non TCP/UDP