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 A1DAD154C0F; Thu, 3 Oct 2024 14:30:32 +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=1727965835; cv=none; b=crnWBhbw0rP//mBCmLS8qLplDJ6bL6hAN63DGoUyCpAi+RbVNfkghtGdiLOP/sn8zpake8UmfvCLhjIwdAmu9yk6Pay7t5Mji1ZHpT4ZPhfHHkVt09NA7rirYTaIGRPIQdBmJ01n5UOMJSHPo31wXHCqlQI0fiPMaschZA5QSKo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727965835; c=relaxed/simple; bh=Kt/zxTObtIhsH6nu6Fr+XIWm1MDAxBJCPQbwGL1FBRc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=SFTTe/fdPWmYkviWwI1cIBPS2aNUaNVtV0bkwY+KClj2EYO+iSz3lmrpo7+3cTf0MalAE6zLhEN6mXQn2P9c5go0mcGSdcFq54DOcncX7pQYR+YBCLRMRZgEDOhakY8rKzLjlqN7jY2mfm387KbsEc6Ib6punAwfin6j+hXPRLQ= 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=CWAFs5lO; 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="CWAFs5lO" 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=bhuIm46xY6cy3xTiaQHo5/KNUnRzYH4635NOH1AsjVA=; b=CWAFs5lO5zWxNrQJ8hdtVvpM35 YuVCzF5kI2GD67kLXD5+stfz9mXd8StVNqx9dRXh4q3AW+bi1jVnLA3H1ccrpDccdp31jAqALJGin xndcIiFRUNgYKEpe5cBeNfeG2+gNk9khSMdwxCRUqA2qU55nkKCh6san+aOrZT/x8Gfs=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1swMqR-008xEd-AU; Thu, 03 Oct 2024 16:30:19 +0200 Date: Thu, 3 Oct 2024 16:30:19 +0200 From: Andrew Lunn To: Qingtao Cao Cc: Qingtao Cao , Heiner Kallweit , Russell King , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/1] net: phy: marvell: avoid bringing down fibre link when autoneg is bypassed Message-ID: <30f9c0d0-499c-47d6-bdf2-a86b6d300dbf@lunn.ch> References: <20241003022512.370600-1-qingtao.cao@digi.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: <20241003022512.370600-1-qingtao.cao@digi.com> On Thu, Oct 03, 2024 at 12:25:12PM +1000, Qingtao Cao wrote: > On 88E151x the SGMII autoneg bypass mode defaults to be enabled. When it is > activated, the device assumes a link-up status with existing configuration > in BMCR, avoid bringing down the fibre link in this case > > Test case: > 1. Two 88E151x connected with SFP, both enable autoneg, link is up with speed > 1000M > 2. Disable autoneg on one device and explicitly set its speed to 1000M > 3. The fibre link can still up with this change, otherwise not. What is actually wrong here? If both ends are performing auto-neg, i would expect a link at the highest speeds both link peers support. If one peer is doing autoneg, the other not, i expect link down, this is not a valid configuration, since one peer is going to fail to auto-neg. If both peers are using forced 1000M, i would expect a link. Andrew