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 3774F1F8723 for ; Tue, 14 Apr 2026 13:04:09 +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=1776171849; cv=none; b=CX1EMS78eMmR1B/QcnXAI/EfaMFeLPubXmH7GWC9mqrddYii7+pEjADShRpcnL9Vs08I/L9OFyTXPIfto4gqesTEqqsWAaPIWQIcR6+5Z4LmlszhR1mZS8h0HSHKvuCspBf2Hi6NIbKQFqmGn3NAKt1bUGXqVfehm7fTJCh3VLY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776171849; c=relaxed/simple; bh=+SdxuvV++RW3Au9ENkYe7TDMNH7gu+U+TpzaE8EMu60=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=bmEnkO1SxWvUPkwvQmK5IrsWRILInjK956RIMLQoxMd3OeXY4OzEEppL3yPRLRDLxcD2g2aY5p8bVrxkgx/cGyWqRTkeSUMdZ2tGWGfsDqa7+SJnaC3A/t0aJ2H/XIygaN9JncrUQ+N+kb/arfOi7GGE05/DtTW6rIruhHgsozQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=h9oAJT39; 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="h9oAJT39" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 64FCFC19425; Tue, 14 Apr 2026 13:04:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776171848; bh=+SdxuvV++RW3Au9ENkYe7TDMNH7gu+U+TpzaE8EMu60=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=h9oAJT39GRuHqt8X4CzT3FAocKIXUrycPfF479DhSGQ9lDYjqZdrVJMMal/khypft uiE8m/T/lSLmTIrK4QZWNc34kZjGFlo/wt5DEA2oaCJcSw7k68zV185MyRzvJ0gf77 gmQqDnU+8WShfOA5yrhzQaTFUgVOE0lRhPJjt6Rbi8PFzGeQSJHVv86Spki/3gY24c a85V+kaLHRCLxXfBwiuGHLaMEVADYE/07rb4xmJQpgYmq0hFqSlY/90+VLZQGnF00L OzZEGAoHbm7cCiw6TAahbBkkvoG2JfZYlUQvV1HFlpnClg1Ukpzqq3uefkRNX+JbU4 dNrPfidGe3fKg== Date: Tue, 14 Apr 2026 15:04:06 +0200 From: Lorenzo Bianconi To: Simon Horman Cc: 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 Message-ID: References: <20260412-airoha-fix-max-mtu-v1-1-333030d0a564@kernel.org> <20260414124011.751922-1-horms@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="Q+gggKPI9waM/m7U" Content-Disposition: inline In-Reply-To: <20260414124011.751922-1-horms@kernel.org> --Q+gggKPI9waM/m7U Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > From: 'Simon Horman' >=20 > 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 >=20 > 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. >=20 > > diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/eth= ernet/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) > > =20 > > static int airoha_dev_open(struct net_device *dev) > > { > > - int err, len =3D ETH_HLEN + dev->mtu + ETH_FCS_LEN; > > struct airoha_gdm_port *port =3D netdev_priv(dev); > > struct airoha_qdma *qdma =3D port->qdma; > > + int err, len =3D ETH_HLEN + dev->mtu; >=20 > Does this regression cause MTU-sized VLAN-tagged frames to be dropped by = the > hardware? >=20 > By limiting the frame size to ETH_HLEN + dev->mtu, the maximum allowed le= ngth > 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 require= s an > 18-byte L2 header, making the total frame size 1518 bytes (excluding FCS). >=20 > Previously, the inclusion of ETH_FCS_LEN inadvertently provided the 4-byte > headroom needed to accommodate a single VLAN tag.=20 >=20 > Could the configuration explicitly account for VLAN headers using VLAN_ET= H_HLEN > instead? ack, thx for pointing this out. I will fix it in v2. Regards, Lorenzo >=20 > [ ... ] --Q+gggKPI9waM/m7U Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTquNwa3Txd3rGGn7Y6cBh0uS2trAUCad47RgAKCRA6cBh0uS2t rPLDAP9Q5H7Gu+YaELSGXFfA19Ve/ujnBdFo02w+qdtwsV1EiwEAz8wT7BGV5Axj dQ8zS8efuQJZOHb4yYvA+gf5P4uGIQ8= =4+Tn -----END PGP SIGNATURE----- --Q+gggKPI9waM/m7U--