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[144.49.247.28]) by smtp-relay.gmail.com with ESMTPS id a92af1059eb24-1b3b566def3sm45142c88.20.2026.11.09.14.14.36 for (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 09 Nov 2026 14:14:37 -0800 (PST) X-Relaying-Domain: broadcom.com X-CFilter-Loop: Reflected Received: by mail-dl1-f69.google.com with SMTP id a92af1059eb24-1383723dfddso1726800c88.0 for ; Mon, 09 Nov 2026 14:14:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; t=1794262475; x=1794867275; darn=vger.kernel.org; h=content-transfer-encoding:content-type:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to :content-type; bh=m2la7If7oS8mGV9E9elp0qEy1slr4e68W5FdYtWr/CM=; b=ZaYbnyy6kadtq3xn0Knu0tWVKlADi3H1KOvvPZujx5l4i8hO9nj9/L5NnpaEoz7T2u QNxliIjePias9+ERexJDJM//pi4Fx56/R9FUYZaVZxZn46FIUv7TObsRFIW+Yz6O4/bi 7nILuRtKJ/zcOW2u+rpH7zzT4I23RApGlWB78= X-Forwarded-Encrypted: i=1; AL+hErHOBGggvgWu5eCtd9pt63z9u3So/ao0R2jrThyc02TnQI97s5KR2lPT/9q4Xrzhbam4piLquhwFjTyNY70=@vger.kernel.org X-Received: by 2002:a05:701b:4590:10b0:143:297c:276c with SMTP id a92af1059eb24-1b3b618ad61mr970033c88.33.1794262475377; Mon, 09 Nov 2026 14:14:35 -0800 (PST) X-Received: by 2002:a05:701b:4590:10b0:143:297c:276c with SMTP id a92af1059eb24-1b3b618ad61mr969982c88.33.1794262474447; Mon, 09 Nov 2026 14:14:34 -0800 (PST) Received: from [10.67.48.245] ([192.19.223.252]) by smtp.gmail.com with ESMTPSA id a92af1059eb24-1b3b56c4e88sm1695896c88.0.2026.11.09.14.14.32 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 09 Nov 2026 14:14:33 -0800 (PST) Message-ID: <229e94bd-28ff-443f-9667-f8f304a2fb0c@broadcom.com> Date: Mon, 9 Nov 2026 14:14:31 -0800 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net v2 2/2] net: bcmgenet: flatten frames that cannot fit the ring To: Nicolai Buchwitz , Doug Berger , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Justin Chen , Broadcom internal kernel review list , Nikolay Aleksandrov , Jason Xing , netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <20261109-nb-genet-txq-thld-net-v2-0-efd8f4be96f2@tipi-net.de> <20261109-nb-genet-txq-thld-net-v2-2-efd8f4be96f2@tipi-net.de> Content-Language: en-US, fr-FR From: Florian Fainelli Autocrypt: addr=florian.fainelli@broadcom.com; keydata= xsBNBFPAG8ABCAC3EO02urEwipgbUNJ1r6oI2Vr/+uE389lSEShN2PmL3MVnzhViSAtrYxeT M0Txqn1tOWoIc4QUl6Ggqf5KP6FoRkCrgMMTnUAINsINYXK+3OLe7HjP10h2jDRX4Ajs4Ghs JrZOBru6rH0YrgAhr6O5gG7NE1jhly+EsOa2MpwOiXO4DE/YKZGuVe6Bh87WqmILs9KvnNrQ PcycQnYKTVpqE95d4M824M5cuRB6D1GrYovCsjA9uxo22kPdOoQRAu5gBBn3AdtALFyQj9DQ KQuc39/i/Kt6XLZ/RsBc6qLs+p+JnEuPJngTSfWvzGjpx0nkwCMi4yBb+xk7Hki4kEslABEB AAHNMEZsb3JpYW4gRmFpbmVsbGkgPGZsb3JpYW4uZmFpbmVsbGlAYnJvYWRjb20uY29tPsLB IQQQAQgAywUCZWl41AUJI+Jo+hcKAAG/SMv+fS3xUQWa0NryPuoRGjsA3SAUAAAAAAAWAAFr ZXktdXNhZ2UtbWFza0BwZ3AuY29tjDAUgAAAAAAgAAdwcmVmZXJyZWQtZW1haWwtZW5jb2Rp bmdAcGdwLmNvbXBncG1pbWUICwkIBwMCAQoFF4AAAAAZGGxkYXA6Ly9rZXlzLmJyb2FkY29t Lm5ldAUbAwAAAAMWAgEFHgEAAAAEFQgJChYhBNXZKpfnkVze1+R8aIExtcQpvGagAAoJEIEx tcQpvGagWPEH/2l0DNr9QkTwJUxOoP9wgHfmVhqc0ZlDsBFv91I3BbhGKI5UATbipKNqG13Z TsBrJHcrnCqnTRS+8n9/myOF0ng2A4YT0EJnayzHugXm+hrkO5O9UEPJ8a+0553VqyoFhHqA zjxj8fUu1px5cbb4R9G4UAySqyeLLeqnYLCKb4+GklGSBGsLMYvLmIDNYlkhMdnnzsSUAS61 WJYW6jjnzMwuKJ0ZHv7xZvSHyhIsFRiYiEs44kiYjbUUMcXor/uLEuTIazGrE3MahuGdjpT2 IOjoMiTsbMc0yfhHp6G/2E769oDXMVxCCbMVpA+LUtVIQEA+8Zr6mX0Yk4nDS7OiBlvOwE0E U8AbwQEIAKxr71oqe+0+MYCc7WafWEcpQHFUwvYLcdBoOnmJPxDwDRpvU5LhqSPvk/yJdh9k 4xUDQu3rm1qIW2I9Puk5n/Jz/lZsqGw8T13DKyu8eMcvaA/irm9lX9El27DPHy/0qsxmxVmU pu9y9S+BmaMb2CM9IuyxMWEl9ruWFS2jAWh/R8CrdnL6+zLk60R7XGzmSJqF09vYNlJ6Bdbs MWDXkYWWP5Ub1ZJGNJQ4qT7g8IN0qXxzLQsmz6tbgLMEHYBGx80bBF8AkdThd6SLhreCN7Uh IR/5NXGqotAZao2xlDpJLuOMQtoH9WVNuuxQQZHVd8if+yp6yRJ5DAmIUt5CCPcAEQEAAcLB gQQYAQIBKwUCU8AbwgUbDAAAAMBdIAQZAQgABgUCU8AbwQAKCRCTYAaomC8PVQ0VCACWk3n+ obFABEp5Rg6Qvspi9kWXcwCcfZV41OIYWhXMoc57ssjCand5noZi8bKg0bxw4qsg+9cNgZ3P N/DFWcNKcAT3Z2/4fTnJqdJS//YcEhlr8uGs+ZWFcqAPbteFCM4dGDRruo69IrHfyyQGx16s CcFlrN8vD066RKevFepb/ml7eYEdN5SRALyEdQMKeCSf3mectdoECEqdF/MWpfWIYQ1hEfdm C2Kztm+h3Nkt9ZQLqc3wsPJZmbD9T0c9Rphfypgw/SfTf2/CHoYVkKqwUIzI59itl5Lze+R5 wDByhWHx2Ud2R7SudmT9XK1e0x7W7a5z11Q6vrzuED5nQvkhAAoJEIExtcQpvGagugcIAJd5 EYe6KM6Y6RvI6TvHp+QgbU5dxvjqSiSvam0Ms3QrLidCtantcGT2Wz/2PlbZqkoJxMQc40rb fXa4xQSvJYj0GWpadrDJUvUu3LEsunDCxdWrmbmwGRKqZraV2oG7YEddmDqOe0Xm/NxeSobc MIlnaE6V0U8f5zNHB7Y46yJjjYT/Ds1TJo3pvwevDWPvv6rdBeV07D9s43frUS6xYd1uFxHC 7dZYWJjZmyUf5evr1W1gCgwLXG0PEi9n3qmz1lelQ8lSocmvxBKtMbX/OKhAfuP/iIwnTsww 95A2SaPiQZA51NywV8OFgsN0ITl2PlZ4Tp9hHERDe6nQCsNI/Us= In-Reply-To: <20261109-nb-genet-txq-thld-net-v2-2-efd8f4be96f2@tipi-net.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-DetectorID-Processed: b00c1d49-9d2e-4205-b15f-d015386d3d5e On 11/9/26 13:53, Nicolai Buchwitz wrote: > bcmgenet_xmit() wants one descriptor more than the frame needs. A 31 > fragment frame needs 32 descriptors, so it is refused on a 32 descriptor > ring, even if the ring is empty. > > As a result nothing is in flight which could wake the queue again. The > watchdog can only hand the same frame back, therefore the queue stays > stopped. > > This needs CONFIG_MAX_SKB_FRAGS >= 31 and a sender which fragments that > finely, for example MSG_ZEROCOPY. > > Linearize those frames instead. > > Fixes: 3948b05950fd ("net: introduce a config option to tweak MAX_SKB_FRAGS") > Signed-off-by: Nicolai Buchwitz Reviewed-by: Florian Fainelli -- Florian