From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 0AD3D399340; Mon, 17 Aug 2026 10:18:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786961882; cv=none; b=B/0E4sIXBN304ppxhPC+MiZdWQZ4eGfJ0h2uPXtAnUsxqU5dYN5Nmq4mFy060Y1UGPlWIp2GtaUJmhLpons+5KngmOWl1KPvRQLa6ryDOOEy/COiqI5Mq//r3doUaDUSitP4CV2TnYTi/a8VW+PnPc2Wa5adYifieRBnHzSQmhc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786961882; c=relaxed/simple; bh=WYFr824Jg2UGcL8s/b+96eo/UlnKUJpf22JY9x9tOZ4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=KPcVQJ+lXsD1l5PdLMoec+08MLpdf7uyCJaRWpwvdqHwwQ6chxO/i3Fm1rKNcFHh9x+C5RbVYddKOXPji6z8WIyvTkhckLbXXtdttXiKKsoha0ttzRjtsaIXtd/FqAIamUBiqZ30R6yFvh35wRdr9NeVodk99WZ44rRuyC5D1Ss= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WnoxnwwN; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="WnoxnwwN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 000DA1F000E9; Mon, 17 Aug 2026 10:17:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786961880; bh=TXBQkyiFLvXRPc/vOwn4FFBd5nq323zoO1sSOJOX4cw=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=WnoxnwwNzxDZ1uTD3Jm53Egy4+C6aqoRoY0GEIURu9TYM82Zq+KqLLAJ/E2+/+UgC M3LKx/OX2d5cuGEO1UZnES5hvb30VCRndCdCmDJLGMHFSiUhJ4tPIkuebjI6x+fVFc 54056sAl+BGJK1Lbbl5FuyrHxcXqwZqkNt2PJuLbhjKopgFXps6Xa+ABEO2rh1Lpi8 85D0gqTYZKc38c3RkDt/Cgbz3XaSYodY+Dyf0yuy0eQfJ4A6+3RbG6kV0jYw6lQ+fT T9FC3OurG4v08tTv0HWDox4ksMeFINLXpqRB2B8uP2i+pZ/0T8/T5jOE0dTqPDugUo aiXwObD4UGM8A== Date: Mon, 17 Aug 2026 11:17:52 +0100 From: Simon Horman To: Stanislav Fomichev Cc: netdev@vger.kernel.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, anthony.l.nguyen@intel.com, przemyslaw.kitszel@intel.com, andrew+netdev@lunn.ch, saeedm@nvidia.com, tariqt@nvidia.com, mbloch@nvidia.com, maxime.chevallier@bootlin.com, mcoquelin.stm32@gmail.com, alexandre.torgue@foss.st.com, aleksander.lobakin@intel.com, magnus.karlsson@intel.com, maciej.fijalkowski@intel.com, sdf@fomichev.me, ast@kernel.org, daniel@iogearbox.net, hawk@kernel.org, john.fastabend@gmail.com, witu@nvidia.com, martin.lau@kernel.org, yoong.siang.song@intel.com, rohan.g.thomas@intel.com, intel-wired-lan@lists.osuosl.org, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, bpf@vger.kernel.org, leon@kernel.org Subject: Re: [PATCH net v2 3/3] net: stmmac: skip queueMaxSDU check for AF_XDP Message-ID: <20260817101752.GY265046@horms.kernel.org> References: <20260813190800.222527-1-sdf@fomichev.me> <20260813190800.222527-4-sdf@fomichev.me> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260813190800.222527-4-sdf@fomichev.me> On Thu, Aug 13, 2026 at 12:08:00PM -0700, Stanislav Fomichev wrote: > Commit c5c3e1bfc9e0 ("net: stmmac: Offload queueMaxSDU from tc-taprio") > was inspired by commit 92a0dcb8427d ("igc: offload queue max SDU from > tc-taprio"), but the igc change does not apply the check to AF_XDP. > > xsk_tx_peek_desc() reserves a completion entry. Continuing without > queuing or completing the descriptor leaves the AF_XDP rings imbalanced, > so remove the check from the zero-copy path. > > The assumptions is that AF_XDP zero-copy traffic bypasses the qdisc, so > taprio's queueMaxSDU check does not apply to this path. > > Fixes: c5c3e1bfc9e0 ("net: stmmac: Offload queueMaxSDU from tc-taprio") > Signed-off-by: Stanislav Fomichev Reviewed-by: Simon Horman