From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Rybchenko Subject: Re: [PATCH] ethdev: fix setting of MAC address Date: Tue, 19 Dec 2017 12:47:04 +0300 Message-ID: References: <20171214171531.10506-1-olivier.matz@6wind.com> <20171219092932.5k5sg3eemfghatkl@glumotte.dev.6wind.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit Cc: Igor Ryzhov , , Thomas Monjalon , Laurent Hardy , To: Olivier MATZ , Ivan Malov Return-path: In-Reply-To: <20171219092932.5k5sg3eemfghatkl@glumotte.dev.6wind.com> Content-Language: en-GB List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 12/19/2017 12:29 PM, Olivier MATZ wrote: > 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 :) We'll send net/sfc patch today/tomorrow to fix it. Thanks, Andrew.