From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from vps0.lunn.ch (vps0.lunn.ch [156.67.10.101]) (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 D1115313281; Fri, 20 Feb 2026 13:36:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=156.67.10.101 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771594580; cv=none; b=TadRiC+jNSNlbpq41BnlgJyRxewt7ERLdrhE1/ApLdfKVnRW7YWkLDA6+T+6kx3GkUMtVMCsOtsrIG4dL3lrkcbmHnI9TerPvQhpY2V7rBgZl/sxpoEiMA5T4t2cmSwOntgLINz1EkiFA8YF1HCE3B/YUX89pDlsuUDJqK3mTmY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771594580; c=relaxed/simple; bh=UZqugDl9YAuEn3qPaV7KYY7wKE1Ep4P6qhkliHaP7Oo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=oZ4K5T02LznLy1xqNw2e6uQpirNs/AtYCniZSzcwkLl3Ny2RPZn5D+iozYq5YsOLlyCW0X5rEfIbpXv+Aazb5AOWtSg+PTmT1HSZwrFx71LWnvoJ89nqNZbHAfN9iPp32GeRZqFYKRtu9HzmsSlCk8adKbcqeTjX8yduAhp+CsM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch; spf=pass smtp.mailfrom=lunn.ch; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b=27qFReLU; arc=none smtp.client-ip=156.67.10.101 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lunn.ch Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="27qFReLU" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Disposition:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:From:Sender:Reply-To:Subject: Date:Message-ID:To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Content-Disposition:In-Reply-To:References; bh=xqKLoTg7Ju7x5pvSrVHpqnVQjdZWB/YWkrxf0VRywQE=; b=27qFReLU4ywzybhAqrHkRUEWtG zRKYmiqL6KlaPTvAe/qOAxxPUFOIClouJS5DHoZ5X2Poc/DH9+ClxYhIyXHux/Z8344fKkGvks9G7 jtyiYLCPz1zWnCGQUAgrShqkwIWhWuvMDWpghD1VGwXli/ztD5KcJoU0NKSWp7g9PxWs=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1vtQfx-0084ZL-7o; Fri, 20 Feb 2026 14:36:09 +0100 Date: Fri, 20 Feb 2026 14:36:09 +0100 From: Andrew Lunn To: "Neeli, Srinivas" Cc: "andrew+netdev@lunn.ch" , "davem@davemloft.net" , "edumazet@google.com" , "kuba@kernel.org" , "pabeni@redhat.com" , "Simek, Michal" , "robh@kernel.org" , "krzk+dt@kernel.org" , "conor+dt@kernel.org" , "richardcochran@gmail.com" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "git (AMD-Xilinx)" Subject: Re: [RFC PATCH 0/8] xilinx: tsn: Add TSN Endpoint Ethernet MAC driver support Message-ID: <28b232f1-5814-4b3a-af28-1eab023743c0@lunn.ch> References: <20260219054911.2017362-1-srinivas.neeli@amd.com> <5f884e29-151a-4ee7-9e1a-d7e1f84d9f6c@lunn.ch> Precedence: bulk X-Mailing-List: netdev@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: On Fri, Feb 20, 2026 at 12:59:16PM +0000, Neeli, Srinivas wrote: > [AMD Official Use Only - AMD Internal Distribution Only] Sorry, i'm not part of AMD... > > So how does the host send a frame out Port 2? Is there an extra header > > on the frame sent by EndPoint, which the switch interprets? > > > > In this RFC, I configured all switch ports in forward mode. As a > result, when a frame is sent from the internal endpoint, it is > flooded to both external ports. To forward packets to a specific > port instead of flooding, either static switch CAM entries need to > be configured or address learning should be enabled so the switch > can learn CAM entries dynamically. Despite not being part of AMD, this part is important. I don't care about how the RFC works, i want to know how the hardware works, to ensure you have the correct choice of DSA vs pure switchdev. Take the example of running Spanning Tree Protocol. The bridge needs to send the BPDU out a specific port. What mechanism is used to do that? It also needs to know which port a BPDU ingressed. Andrew