From mboxrd@z Thu Jan  1 00:00:00 1970
From: Bruce Richardson <bruce.richardson@intel.com>
Subject: Re: [PATCH v2] ether: use a default for max Rx frame
 size in configure()
Date: Fri, 7 Apr 2017 09:24:08 +0100
Message-ID: <20170407082407.GA11816@bricha3-MOBL3.ger.corp.intel.com>
References: <1490288768-8114-1-git-send-email-Andriy.Berestovskyy@cavium.com>
 <1490356325-15434-1-git-send-email-Andriy.Berestovskyy@caviumnetworks.com>
 <F5DF4F0E3AFEF648ADC1C3C33AD4DBF16EDEBB0A@SHSMSX101.ccr.corp.intel.com>
 <189fbba9-f97b-9bb6-e9fa-9669fd0ffa0a@caviumnetworks.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Cc: "Yang, Qiming" <qiming.yang@intel.com>,
 Thomas Monjalon <thomas.monjalon@6wind.com>, "dev@dpdk.org" <dev@dpdk.org>
To: Andriy Berestovskyy <Andriy.Berestovskyy@caviumnetworks.com>
Return-path: <dev-bounces@dpdk.org>
Received: from mga02.intel.com (mga02.intel.com [134.134.136.20])
 by dpdk.org (Postfix) with ESMTP id E2BA02C5
 for <dev@dpdk.org>; Fri,  7 Apr 2017 10:24:12 +0200 (CEST)
Content-Disposition: inline
In-Reply-To: <189fbba9-f97b-9bb6-e9fa-9669fd0ffa0a@caviumnetworks.com>
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <http://dpdk.org/ml/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://dpdk.org/ml/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <http://dpdk.org/ml/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>

On Mon, Mar 27, 2017 at 10:38:13AM +0200, Andriy Berestovskyy wrote:
> Hey Qiming,
> 
> On 27.03.2017 08:15, Yang, Qiming wrote:
> > I don't think this is a bug. Return errors when configure an invalid max_rx_pkt_len is suitable for this generic API.
> 
> It is not a bug, it is an inconsistency. At the moment we can set
> max_rx_pkt_len for normal frames and if it is out of range a default value
> will be used instead.
> 
> IMO we should expect the same behavior from the same function for the jumbo
> frames.
> 
> So at the moment we have:
> jumbo == 0, max_rx_pkt_len == 0, result: max_rx_pkt_len = ETHER_MAX_LEN
> jumbo == 0, max_rx_pkt_len == 1200, result: max_rx_pkt_len = 1200

Is this really the case right now. My understanding was that when jumbo
== 0 max_rx_pkt_len is ignored. At least on Intel NICS, I believe the
max_rx_pkt_len is always 1518 unless jumbo frame support is explicitly
enabled. [Perhaps the driver maintainers can confirm this for me.]

Regards,
/Bruce