From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0ACD83E5ECE for ; Tue, 14 Apr 2026 12:40:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776170427; cv=none; b=KEs+QZp+ZGd+BalPBQWbrR5usDJD2CwOJDRTY9iLKIoUM2VqCvZPQzRXIwzNBR18RJGAN2WKj78edt89tb7XDE54zGxcHJEhsaosGQHdTwKE1gw/Z5CL850iJTDVXt3Xw1eo0qGTCzsBrA9WV6iIHCBq0F/gSCSEVTJWnPBoT84= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776170427; c=relaxed/simple; bh=IPBwqh9d3tDbxmlKfehIU4Pa/JiRA+IdViszBuMtYAg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bBvWKHYFpr8tp50vjBSj1CXh+bTWtuVA/AUIda9ALySUur0KTaBCNH8cwLyS4EBJ8Y/yegqKK9KdnoTmrRUcxicHBI50Pp/0SNcYu2jDvwm0wfpR+0gwlPcCraWQgf0j7detlqWQsmMzFBWvV7GcZK64awPWAyj4FIwPnkiTJuw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=l+o6JimJ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="l+o6JimJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9A47EC19425; Tue, 14 Apr 2026 12:40:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776170426; bh=IPBwqh9d3tDbxmlKfehIU4Pa/JiRA+IdViszBuMtYAg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=l+o6JimJSyx0n76jesd6mCHnnhRw0R97PxIu1yNKcBHkqXebFznuJ4wQvjRE2Jf0r H5pS6nhw8wsbwz6zcAlqNG0+5JM0yUpBW64Q0KUIC/saKUWa8CXBo8CLl0BM2tYwJe /yC+jTNFhqchoZlVTqiV/NH+mGZ5zCTUFKmUfQ5amTHKmZan/hGLqkgcDOh6kqa5Un PP3SGIGAMjuuVAOoIcpq4PAc+qTuDhjECcYVCgazCVL7I4txSLrm4WqhtAywLG8ZT5 8OAv6dyZbOFWMoLsr/jQnii/m3pNJqKNIaQz8rsCTasnzS6znKczm1Xh/+bt/nOdN9 Y5Du/+H/533tQ== From: Simon Horman To: lorenzo@kernel.org Cc: 'Simon Horman' , andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, netdev@vger.kernel.org Subject: Re: [PATCH net] net: airoha: Fix max TX packet length configuration Date: Tue, 14 Apr 2026 13:40:11 +0100 Message-ID: <20260414124011.751922-1-horms@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260412-airoha-fix-max-mtu-v1-1-333030d0a564@kernel.org> References: <20260412-airoha-fix-max-mtu-v1-1-333030d0a564@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: 'Simon Horman' This is an AI-generated review of your patch. The human sending this email has considered the AI review valid, or at least plausible. Full review at: https://sashiko.dev --- net: airoha: Fix max TX packet length configuration This commit fixes the MTU configuration for the Airoha driver by removing ETH_FCS_LEN from the maximum TX packet length, matching the hardware documentation which states the register does not include the FCS length. > diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c > index c14cdce588a7c..a81ffda72b39f 100644 > --- a/drivers/net/ethernet/airoha/airoha_eth.c > +++ b/drivers/net/ethernet/airoha/airoha_eth.c > @@ -1629,9 +1629,9 @@ static void airoha_update_hw_stats(struct airoha_gdm_port *port) > > static int airoha_dev_open(struct net_device *dev) > { > - int err, len = ETH_HLEN + dev->mtu + ETH_FCS_LEN; > struct airoha_gdm_port *port = netdev_priv(dev); > struct airoha_qdma *qdma = port->qdma; > + int err, len = ETH_HLEN + dev->mtu; Does this regression cause MTU-sized VLAN-tagged frames to be dropped by the hardware? By limiting the frame size to ETH_HLEN + dev->mtu, the maximum allowed length becomes 1514 bytes for a standard 1500 MTU. An Ethernet frame containing a standard 802.1Q VLAN tag and a maximum-sized 1500-byte IP payload requires an 18-byte L2 header, making the total frame size 1518 bytes (excluding FCS). Previously, the inclusion of ETH_FCS_LEN inadvertently provided the 4-byte headroom needed to accommodate a single VLAN tag. Could the configuration explicitly account for VLAN headers using VLAN_ETH_HLEN instead? [ ... ]