From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Monjalon Subject: Re: [dpdk-stable] [PATCH v1] net/tap: fix CRC stripping capability report Date: Mon, 12 Feb 2018 18:55:22 +0100 Message-ID: <5072632.Aql229SuCI@xps> References: <1518446598-24238-1-git-send-email-ophirmu@mellanox.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Cc: dev@dpdk.org, Pascal Mazon , Olga Shern To: Ophir Munk Return-path: Received: from out1-smtp.messagingengine.com (out1-smtp.messagingengine.com [66.111.4.25]) by dpdk.org (Postfix) with ESMTP id 10AB21B3CF for ; Mon, 12 Feb 2018 18:55:32 +0100 (CET) In-Reply-To: <1518446598-24238-1-git-send-email-ophirmu@mellanox.com> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" The title should be "add CRC stripping capability". 12/02/2018 15:43, Ophir Munk: > CRC stripping is executed outside of TAP PMD scope. There is no > prevention that TAP reports on Rx CRC stripping capability. We could mention that the CRC stripping is done in the kernel. > It is especially required when TAP is operating as failsafe sub-device > with another PCI sub-device which supports CRC stripping. > In the corrupted code TAP did not report on this capability which > caused failsafe to not report on it as well. You discover the bug with failsafe but it is not related at all. I think you squeeze this part of the explanation. > The fix is for TAP to report that Rx CRC stripping is supported. > > Fixes: 95ae196ae10b ("net/tap: use new Rx offloads API") I don't think it is a root cause. This capability is missing from day one: Fixes: 02f96a0a82d1 ("net/tap: add TUN/TAP device PMD") > Cc: stable@dpdk.org > > Signed-off-by: Ophir Munk