From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B1C85D29C2E for ; Mon, 19 Jan 2026 16:14:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=mLMCaEGCjPkN2Mm2sQaGKmatY08Aupz94K2K6BZWWzg=; b=YhYqX4urLpoUeIDi6Ycze+2e7t 16lYG/jl0EFPKK8PHuBZEKxOzlN9bo3+8XaVPtvMbEddWm363zd0K2WTZj+qgJ7IuirlcKoWxYWGP tY4XsoGFrz9IVrC5dUnnhYYufoxwCMNroAhEDv2ryF+JYvI1v8Ewrr6f1kKuZdYGOloDebgUX1EdK eRR6vrWApCOyUppFfJKzQmEB9rXaDrnVZ/TGnGxsHYxUIkP87wXVL7djmZq9rw/SzFQEOtvzHDz+0 JFMZCZWxIsm1QDwO4gQ+Hz/6kn/AwBBH9x9B7/qusC8RqmN268hTiZzURCg8Poh8jQIwYRym7lM7s Lza4vKpQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vhrts-00000002RBv-30T2; Mon, 19 Jan 2026 16:14:46 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vhrtn-00000002RBi-1CbQ; Mon, 19 Jan 2026 16:14:42 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 49B2460055; Mon, 19 Jan 2026 16:14:38 +0000 (UTC) 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> 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> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org --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--