From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from proxy.6wind.com (host.76.145.23.62.rev.coltfrance.com [62.23.145.76]) by dpdk.org (Postfix) with ESMTP id 9FE8F1B019; Tue, 19 Dec 2017 10:29:45 +0100 (CET) Received: from core.dev.6wind.com (unknown [10.0.0.1]) by proxy.6wind.com (Postfix) with ESMTPS id 9E1FB116829; Tue, 19 Dec 2017 10:21:06 +0100 (CET) Received: from [10.16.0.195] (helo=6wind.com) by core.dev.6wind.com with smtp (Exim 4.84_2) (envelope-from ) id 1eREDN-0008Bh-Vj; Tue, 19 Dec 2017 10:29:34 +0100 Received: by 6wind.com (sSMTP sendmail emulation); Tue, 19 Dec 2017 10:29:33 +0100 Date: Tue, 19 Dec 2017 10:29:33 +0100 From: Olivier MATZ To: Andrew Rybchenko Cc: Igor Ryzhov , dev@dpdk.org, Thomas Monjalon , Laurent Hardy , stable@dpdk.org Message-ID: <20171219092932.5k5sg3eemfghatkl@glumotte.dev.6wind.com> References: <20171214171531.10506-1-olivier.matz@6wind.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) Subject: Re: [dpdk-dev] [PATCH] ethdev: fix setting of MAC address X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 19 Dec 2017 09:29:45 -0000 Hi, On Mon, Dec 18, 2017 at 02:38:55PM +0300, Andrew Rybchenko wrote: > On 12/18/2017 01:53 PM, Igor Ryzhov wrote: > > > > On Mon, Dec 18, 2017 at 1:35 PM, Andrew Rybchenko > > > wrote: > > > > On 12/14/2017 08:15 PM, Olivier Matz wrote: > > > > From: Laurent Hardy > > > > > > When a new mac address is set, it is saved in dev->data->mac_addrs > > before the ethdev handler is called. > > > > First, it is inconsistent with the other ethdev functions > > rte_eth_dev_mac_addr_remove() and rte_eth_dev_mac_addr_add(). > > > > Moreover, it prevents the drivers from wrongly comparing the > > old address > > and the new one, like it's done in i40evf driver: > > > >         if (is_same_ether_addr(mac_addr, dev->data->mac_addrs)) > >                 return; > > > > Fixes: 943c2d899a0c ("net/i40e: set VF MAC from VF") > > Fixes: 854d8ad4ef68 ("ethdev: add default mac address modifier") > > Cc: stable@dpdk.org > > > > Signed-off-by: Laurent Hardy > > > > --- > >   lib/librte_ether/rte_ethdev.c | 4 ++-- > >   1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/lib/librte_ether/rte_ethdev.c > > b/lib/librte_ether/rte_ethdev.c > > index 4f492e3db..297c02a54 100644 > > --- a/lib/librte_ether/rte_ethdev.c > > +++ b/lib/librte_ether/rte_ethdev.c > > @@ -2643,11 +2643,11 @@ > > rte_eth_dev_default_mac_addr_set(uint16_t port_id, struct > > ether_addr *addr) > >         dev = &rte_eth_devices[port_id]; > >         RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->mac_addr_set, > > -ENOTSUP); > >   +     (*dev->dev_ops->mac_addr_set)(dev, addr); > > + > >         /* Update default address in NIC data structure */ > >         ether_addr_copy(addr, &dev->data->mac_addrs[0]); > >   -     (*dev->dev_ops->mac_addr_set)(dev, addr); > > - > >         return 0; > >   } > > > > > > NACK, unfortunately it will break net/sfc in one of branches when > > a new MAC > > is set using restart. It relies on the fact that a new MAC is > > already available in > > device data. > > > > > > Hello Andrew, > > > > Don't you think that it's not correct that net/sfc works that way? > > > > If we go further, dev->dev_ops->mac_addr_set not only should be called > before ether_addr_copy. > > It should return status code, and in case of error ether_addr_copy > > shouldn't be > called at all. > > Am I wrong? Yes, I also have the same feeling. > Current behaviour is convenient. Alternative will require copy of MAC > address > to set in device private data and one more copy in the function to rollback > in > the case of failure. If there are good reasons to change behaviour, I don't > mind but PMDs should be reviewed carefully and fixed before the change. Right. The first version of the patch was just a fix of the i40e code, which was of course less risky. But we finally decided to to that way for consistency. I will review the other PMDs and send a v2 that should not break them. If you have any guidelines for net/sfc, they will be welcome :) Thanks for the review. Olivier