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 20D2E1FF1BF; Fri, 4 Jul 2025 17:53:18 +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=1751651600; cv=none; b=BtzTQfFva6jcDo8MQeYn5hl715OSCCt4S6Vj+Cvs8fX/3N008Oh8DBjwVZZW1d936VZns7mRGTY8DUOcK1gIu3ibo106vaXHzIIlURn+bU+A925VggYbfRUQ9QbCB3E0kkf8QnMrC0MFHRm+LmvEoR+d9LEw02AWdd05rM3OsTE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751651600; c=relaxed/simple; bh=a02edtCij3cZvXYBmVyT4BxwOjMAk4YCSqwdFh9SoSg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=uBKzcFIJuMEJBbfLzfI2zFg3r1BLaYLl94XLxPts29QA51TS7GfgRuo3XFzyxZ58wJS4NNUW9kAzpBbdGoWj2g6TBXeFRQk69A3alqM8HXw8aVWtrhvnfngWWIbwVjut9N4iAGa/eLg13MCs+X2IxqUzi94exn1XXSqpg4XB3Io= 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=CsAWwwTj; 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="CsAWwwTj" 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=hqYSMmJaUKMrrQ0d6K8F5kvg+JtqUzGt7LbPy35JGiE=; b=CsAWwwTjKoxhQWnxNQ/MvD6naC 4tRlFhzx+bbXX5d/2JZbjciPl5qq4zJZHhOZ6Bp0UpzRZAzeUkisQRgJxkay57kwwInYfYLdW7/ms p4iPrrpbn2DeYp5h+oEr46Nrdc/s0/KQMuTc9rN92oqV3IrZGpjO/V7GpXmYlR6BYrsE=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1uXkay-000HBf-VY; Fri, 04 Jul 2025 19:53:08 +0200 Date: Fri, 4 Jul 2025 19:53:08 +0200 From: Andrew Lunn To: Nikita Yushchenko Cc: Michael Dege , Yoshihiro Shimoda , Niklas =?iso-8859-1?Q?S=F6derlund?= , Paul Barker , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/3] net: renesas: rswitch: R-Car S4 add HW offloading for layer 2 switching Message-ID: <27047e61-8307-472d-96dd-1e5b89dc427f@lunn.ch> References: <20250704-add_l2_switching-v1-0-ff882aacb258@renesas.com> <4310ae08-983a-49bb-b9fe-4292ca1c6ace@lunn.ch> <79a57427-fd4a-4b9a-a081-cf09b649a20e@cogentembedded.com> 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: <79a57427-fd4a-4b9a-a081-cf09b649a20e@cogentembedded.com> On Fri, Jul 04, 2025 at 11:05:14AM +0200, Nikita Yushchenko wrote: > > Looking at the code, it is not clear to me what would happen with: > > > > ip link add name br0 type bridge > > ip link set dev tsn0 master br0 > > ip link set dev br0 up > > ip link set dev tsn0 up > > ip link add name br1 type bridge > > ip link set dev tsn1 master br1 > > ip link set dev br1 up > > ip link set dev tsn1 up > > Per design, it shall enable hardware forwarding when two ports are in the same brdev. So in this case, the hardware offload has been reserved by br0, but is in fact never used, since there is only one port in the bridge. If i was to then do ip link set dev tsn2 master br1 ip link set dev tsn2 up br1 would not be offloaded, but done in software. Andrew