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 4FEAC1A316E for ; Mon, 19 Jan 2026 16:14:38 +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=1768839278; cv=none; b=t2GddCdmXPojxNjdJd9t9uj15DNuN+W8XsRv+e5Ek/RPUEPqHkT6RYcPFweToMCAQm0oEMtUrA/gFpy48HfTJQYVxZI/REzPDfNA5vZnVVs04wYWJC+bjxX0jUkjlBrThxnoEPr7EOYqawK51FJIQwCS0J0VTqSDV2SYckaHCvw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768839278; c=relaxed/simple; bh=lSfsVlCqyZvf6pA1XPog974EukldB/XYySTEmAm9AVY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NKoX8exDy5Qk9sKq7PUtxiWAytA5PucoHzQkXf6XqoJ2NzYDk+NLz8hBddiGKTIf2gn1A2pkLI7FTMLmcnfuZdypQ7mjkVOzguRbhazFfvxiP0/G+lm5vkB3+JVuIHKPSE3XRYYypUGT/yI3sPBrGVvluuSXMjReSZQV/C/Dyys= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=W0qXyLKY; 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="W0qXyLKY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A157FC116C6; Mon, 19 Jan 2026 16:14:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768839278; bh=lSfsVlCqyZvf6pA1XPog974EukldB/XYySTEmAm9AVY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=W0qXyLKYlu8MTMpc+PeSAw5wrgSVGYKLiidFDfPtqfjHPKJ5owqrFpAQUytFgwaCx Edof5E5tvwaMud5QVyJEgsRq4rAOpl01lKEJmFYfWW1c8GQNvd8hA80FkkmHSiPa5F LOWX2t4UboNXW+DFSjaHME8VvT7MLmV8xuGW4dbpUY0wwv+FLf65blXLLtCkkjG3ex pIsXuJPKVkKgpCx6gD8e70FCcuXRwG4bbJ+6fNrxeU/UtAQ8VH/vYAvwoLwyIr69RN m6YciAeGPSU0wKIoIkhffEUIvRtouSRbBEmt9r9lcbTFkEgeIvri1io0PDDAWT8x5Y G0BLP48bm4Kpg== Date: Mon, 19 Jan 2026 17:14:35 +0100 From: Lorenzo Bianconi To: Sayantan Nandy Cc: linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, netdev@vger.kernel.org, sayantan.nandy@airoha.com, bread.hsu@airoha.com, kuldeep.malik@airoha.com, aniket.negi@airoha.com, brown.huang@airoha.com Subject: Re: [PATCH net-next v3] net: airoha_eth: increase max MTU to 9220 for DSA jumbo frames Message-ID: References: <20260119073658.6216-1-sayantann11@gmail.com> 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="J2jysX/UvlOutc68" Content-Disposition: inline In-Reply-To: <20260119073658.6216-1-sayantann11@gmail.com> --J2jysX/UvlOutc68 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable >=20 > The industry standard jumbo frame MTU is 9216 bytes. When using the DSA > subsystem, a 4-byte tag is added to each Ethernet frame. >=20 > Increase AIROHA_MAX_MTU to 9220 bytes (9216 + 4) so that users can set a > standard 9216-byte MTU on DSA ports. >=20 > The underlying hardware supports significantly larger frame sizes > (approximately 16K). However, the maximum MTU is limited to 9220 bytes > for now, as this is sufficient to support standard jumbo frames and does > not incur additional memory allocation overhead. >=20 >=20 > Signed-off-by: Sayantan Nandy Acked-by: Lorenzo Bianconi > --- > v3: > - Document that hardware supports larger MTU (~16K), but limit to 9220 fo= r now > - Target net-next (netdev/main) as this is a feature enhancement > - No functional changes >=20 > v2: > - Clarified commit message regarding DSA tag overhead >=20 > drivers/net/ethernet/airoha/airoha_eth.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) >=20 >=20 > diff --git a/drivers/net/ethernet/airoha/airoha_eth.h b/drivers/net/ether= net/airoha/airoha_eth.h > index fbbc58133364..20e602d61e61 100644 > --- a/drivers/net/ethernet/airoha/airoha_eth.h > +++ b/drivers/net/ethernet/airoha/airoha_eth.h > @@ -21,7 +21,7 @@ > #define AIROHA_MAX_NUM_IRQ_BANKS 4 > #define AIROHA_MAX_DSA_PORTS 7 > #define AIROHA_MAX_NUM_RSTS 3 > -#define AIROHA_MAX_MTU 9216 > +#define AIROHA_MAX_MTU 9220 > #define AIROHA_MAX_PACKET_SIZE 2048 > #define AIROHA_NUM_QOS_CHANNELS 4 > #define AIROHA_NUM_QOS_QUEUES 8 > --=20 > 2.43.0 >=20 --J2jysX/UvlOutc68 Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTquNwa3Txd3rGGn7Y6cBh0uS2trAUCaW5YawAKCRA6cBh0uS2t rBEmAQDHxUyhIPGHm22GhCpC1m40BZZI353lz/CrFQ+Y1qkV/wD+LNlBeyE/03VJ edunfoIYQPT9G31c6f8yeJVTeuFmKg8= =KIMb -----END PGP SIGNATURE----- --J2jysX/UvlOutc68--