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 E2DF982866 for ; Sat, 11 Jul 2026 15:16:39 +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=1783783001; cv=none; b=fY4wHOo60D3wGS8Jq46NSG2QO+CaATsFyqWQKH255uTfXEKz1jiQbw6XuYl6+sgAAeijN8PjfUB5VWrYtO/rCdUygjplETAUyVglNU3b3dxxdKKNQ4xE3AD8ao1GKmd+9keUjivFbI/k9QGSpXO/74mpnBCaxfxUrBbORYQ4ZLk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783783001; c=relaxed/simple; bh=nh7AGmHVKrAU7t1AcaynZLcca/AOh35ebCYwatgCXp0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=YfVV2k1CNg9lKuB8ZF2QOnbjhE58jDNbtBRPlJY4fRT3bv8rAoajpeDx4EjRpxHzuauQ0kGRCeRPho7uJpZDlrkjJq7BbRBr/QRvKjcgQgzh8g+/Qh/mrHX7Ym7dgwwqZuhvsV+DypN8avLfBM+0DYtr6t/WuFuEA6Gh7yK3Xwo= 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=M6O4pOGf; 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="M6O4pOGf" 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=s8VVxditPMEF3PVmMbBKB0SHgQPyj5KXM+8qvAn3ZEY=; b=M6O4pOGfSSDiOeQxhgp0M6AYlK gEh/4UBPIRbMhpH+oZBEErCN0qQMF9M5J2VR1ph87DBnH8QGogqVELGaoZ/CpL4AV4R1pH2ImDEdI 3WLoGy1VcFmmmRyzK4Q5BJVqE/asH/lJR5v7sLahrwZUdL6vCf1iUA2jePscDnEV7WgU=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1wiZRS-00Bn5J-GB; Sat, 11 Jul 2026 17:16:34 +0200 Date: Sat, 11 Jul 2026 17:16:34 +0200 From: Andrew Lunn To: Alexander Duyck Cc: Lee Trager , "Das, Shubham" , "Srinivasan, Vijay" , Maxime Chevallier , "netdev@vger.kernel.org" , "mkubecek@suse.cz" , "D H, Siddaraju" , "Chintalapalle, Balaji" , "Lindberg, Magnus" , "niklas.damberg@ericsson.com" , "Wirandi, Jonas" Subject: Re: Ethtool : PRBS feature Message-ID: <63b07d12-d337-465b-a4a8-b8b0771986f0@lunn.ch> References: <26d44b09-d72c-4e23-84a6-3d0ea4a521ef@lunn.ch> <705f6fcb-e0e2-4898-bf83-78c38f32f505@trager.us> <46f714b7-ec6e-4b26-9ff8-b7f27f11fe33@trager.us> <4ccc869f-a724-41fc-9bfc-da5332f54790@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: > Looks like they are different derivations of the polynomial for the > given pattern. For example PRBS11 is 1 + x^9 + x^11 802.3 section "72.6.10.2.6 Training pattern" agrees with you. , but PRBS11_0 is 1 > + x^5 + x^6 + X^10 + x^11. That is one thing to think about. When we > say PRBS7 the assumption is we are all talking about 1 + x^6 + x^7 for > the polynomial. I could be missing it, but i could not quickly find PRBS7 in the standard! > We may want to have that clearly recorded somewhere so > there isn't any confusion on which polynomials we are using for this > testing as there is always a risk that somebody is playing with > bleeding edge hardware and ends up defining a PRBS polynomial > differently than what is expected. I would probably give a reference to 802.3, at least for standard tests. If a vendor has made up their own test sequences then yes, there needs to be a clear definition of what it is. > I almost wonder if we couldn't > define the sequence as a bitmap instead of an enum with each bit > representing which fields are in the sequence. Not everything is a polynomial. Look at SSPQR, 120.5.11.2.3 SSPRQ test pattern. Andrew