From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Monjalon <thomas@monjalon.net>
Subject: Re: [PATCH] app/testpmd: do not enable Rx offloads by
	default
Date: Thu, 25 Jan 2018 10:04:11 +0100
Message-ID: <60691740.PPs9Gye6m2@xps>
References: <1516695081-178919-1-git-send-email-motih@mellanox.com>
 <6A0DE07E22DDAD4C9103DF62FEBC09093B715D7A@shsmsx102.ccr.corp.intel.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7Bit
Cc: Moti Haimovsky <motih@mellanox.com>, dev@dpdk.org, shahafs@mellanox.com,
 ferruh.yigit@intel.com
To: "Lu, Wenzhuo" <wenzhuo.lu@intel.com>
Return-path: <dev-bounces@dpdk.org>
Received: from out4-smtp.messagingengine.com (out4-smtp.messagingengine.com
 [66.111.4.28]) by dpdk.org (Postfix) with ESMTP id 3526E1B1C5
 for <dev@dpdk.org>; Thu, 25 Jan 2018 10:04:59 +0100 (CET)
In-Reply-To: <6A0DE07E22DDAD4C9103DF62FEBC09093B715D7A@shsmsx102.ccr.corp.intel.com>
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <https://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: <https://dpdk.org/ml/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>

25/01/2018 02:11, Lu, Wenzhuo:
> > --- a/app/test-pmd/testpmd.c
> > +++ b/app/test-pmd/testpmd.c
> > @@ -305,9 +305,7 @@ struct fwd_engine * fwd_engines[] = {
> >   */
> >  struct rte_eth_rxmode rx_mode = {
> >  	.max_rx_pkt_len = ETHER_MAX_LEN, /**< Default maximum frame
> > length. */
> > -	.offloads = (DEV_RX_OFFLOAD_VLAN_FILTER |
> > -		     DEV_RX_OFFLOAD_VLAN_STRIP |
> > -		     DEV_RX_OFFLOAD_CRC_STRIP),
> > +	.offloads = 0,
> 
> Change the default behavior may trigger other problems. I think TX offload could be a good reference. Get the capability and check what's supported first, then ignore the not supported functions with printing a warning but not block anything...

I agree that we should check the capabilities before requesting an offload.
But I disagree on another point: we should not enable an offload if the
user did not request it explicitly. It makes things unclear.
This is a testing tool, it should be close to the ethdev API behavior.

Why these offload flags are silently enabled?