From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 92680511E90; Wed, 30 Sep 2026 18:29:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790792982; cv=none; b=UZu65sWkIr/kJaygxntqxiobfGteFwC88NhZgRwOZSlyylk6KuewbFTNQ5CDeOuqZxOG7aVUMNhaYFRJYLMWUny+eu3bgam97nVePxiFKXx52x1bf7JgZtrCxOp2XP0svMd1wKevjVAC07viTIvI0fhjqlAN/fYlHpEoBD69QJU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790792982; c=relaxed/simple; bh=W7b7fF+CcCWziV12h9ZawqHaoD5h7WS7WPY2/C/oS+4=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=vA0xM7SvH1kKEdnJBcIpLn49eQm1y0Ivhb0OChrXDYh5UQuobxNMM/Vj1Bl+oR32GZfGbebuDW7a84aa1Gch2RwtQ/PThckNIqez8ljRXVUDZ3atPsPLwk29/TT12bSlLciaol1j8b8Q3nvMxU0uhnnT/VWxNsdDSD8eM6IXVQ4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=KRIlOpAc; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=KQIIET6G; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="KRIlOpAc"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="KQIIET6G" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1790792978; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=FMowwEW9SgkF7w5iLzPCCh27f7/yKSZJ5Waoj5oObuQ=; b=KRIlOpAckpwNf3q4te5d7Z8BCFFcVbx877vgc+0iol1UniyUDYFfSbCbNNEOB+trELQ/bH owT3pVxnvErc3k4uC6fstJzGlcdm9icAFYJSqy4gVH8+4yH9NyOwni2vu5Ju+VBcqElnI0 /IKOvhjD5P2r69HPMpAZE69bfXzILHALY4d2tmHQiGvUGpa5oATOZhq9Zqo/jGlcQzITUC WRT4GAAx0M9qUdjyFXE4xqtYyiPFiV1yV46qXUWFqX4xbezCRmEhNXyy/2kQEgUue/nRU+ Gy9fEIhhFUBqiBeJ8BQxfi4aIcC+CE7I7ItcREheXlEkbg5KNuzgH5OuBUUugA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1790792978; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=FMowwEW9SgkF7w5iLzPCCh27f7/yKSZJ5Waoj5oObuQ=; b=KQIIET6Ge8hjgDvhQFH5obMl7TV9T3erMZxyR46oBTskqn7DoUFQKOt5SAgZUUivJgRGZG Qoikwf7M2WYDrDAQ== Subject: Re: [PATCH net-next v3 8/8] net: dsa: soce: Disable unsupported hardware STP From: Vasilij Strassheim To: Andrew Lunn Cc: Rob Herring , Krzysztof Kozlowski , Conor Dooley , Vladimir Oltean , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Russell King , Andrew Lunn , Heiner Kallweit , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Martin Kaistra , Benedikt Spranger Date: Wed, 30 Sep 2026 20:29:37 +0200 In-Reply-To: References: <20260923-devel-vstrassheim-soce-dsa-ml-v3-0-ddebafcb9ba7@linutronix.de> <20260923-devel-vstrassheim-soce-dsa-ml-v3-8-ddebafcb9ba7@linutronix.de> Organization: Linutronix GmbH Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Sat, 2026-09-26 at 01:24 +0200, Andrew Lunn wrote: > On Wed, Sep 23, 2026 at 12:39:35PM +0200, Vasilij Strassheim wrote: > > The driver does not implement hardware STP offloading yet. >=20 > What exactly do you mean by STP offload? Can it do the actual > protocol? No DSA switch can do that, we always use the software > implementation. I'm not even sure it is possible to offload the actual > protocol. That's not a complete offload. The documentation says: "The Spanning Tree protocols is supported as a mixed hardware and software solution. In the hardware section, IP core is in charge of forwarding BPDU frames to/from the CPU port and managing frames according to the STP port states." And: "Spanning Tree (STP/RSTP/MSTP) algorithm runs in a software application in the CPU. The CPU is in charge of configuring the switch port states based on the processed BPDU frames." There are a few registers for this. However, it's enough to just turn off the feature and use only the software implementation in Linux. I will update the documentation accordingly and stop using the term =E2=80=9Coffloading=E2=80=9D to avoid confusion. >=20 > Andrew Thanks, Vasilij