From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 1139743D51; Tue, 26 Mar 2024 12:15:12 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 8FD5140265; Tue, 26 Mar 2024 12:15:11 +0100 (CET) Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by mails.dpdk.org (Postfix) with ESMTP id D2F0540261 for ; Tue, 26 Mar 2024 12:15:09 +0100 (CET) Received: from mail.maildlp.com (unknown [172.19.163.174]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4V3nFm07hrzwQJM; Tue, 26 Mar 2024 19:12:28 +0800 (CST) Received: from kwepemm600004.china.huawei.com (unknown [7.193.23.242]) by mail.maildlp.com (Postfix) with ESMTPS id 34F521400DD; Tue, 26 Mar 2024 19:15:07 +0800 (CST) Received: from [10.67.121.59] (10.67.121.59) by kwepemm600004.china.huawei.com (7.193.23.242) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Tue, 26 Mar 2024 19:15:06 +0800 Message-ID: Date: Tue, 26 Mar 2024 19:15:05 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Subject: Re: [PATCH v2 1/6] ethdev: support setting lanes To: Thomas Monjalon , huangdengdui , Damodharam Ammepalli CC: , , , , , , , , , , , References: <20240312075238.3319480-4-huangdengdui@huawei.com> <3325989.AxlXzFCzgd@thomas> <68ee0a54-c0b4-293c-67ee-efed8964c33b@huawei.com> <3628913.0YcMNavOfZ@thomas> From: "lihuisong (C)" In-Reply-To: <3628913.0YcMNavOfZ@thomas> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.67.121.59] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemm600004.china.huawei.com (7.193.23.242) X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org 在 2024/3/26 18:30, Thomas Monjalon 写道: > 26/03/2024 02:42, lihuisong (C): >> 在 2024/3/25 17:30, Thomas Monjalon 写道: >>> 25/03/2024 07:24, huangdengdui: >>>> On 2024/3/22 21:58, Thomas Monjalon wrote: >>>>> 22/03/2024 08:09, Dengdui Huang: >>>>>> -#define RTE_ETH_LINK_SPEED_10G RTE_BIT32(8) /**< 10 Gbps */ >>>>>> -#define RTE_ETH_LINK_SPEED_20G RTE_BIT32(9) /**< 20 Gbps */ >>>>>> -#define RTE_ETH_LINK_SPEED_25G RTE_BIT32(10) /**< 25 Gbps */ >>>>>> -#define RTE_ETH_LINK_SPEED_40G RTE_BIT32(11) /**< 40 Gbps */ >>>>>> -#define RTE_ETH_LINK_SPEED_50G RTE_BIT32(12) /**< 50 Gbps */ >>>>>> -#define RTE_ETH_LINK_SPEED_56G RTE_BIT32(13) /**< 56 Gbps */ >>>>>> -#define RTE_ETH_LINK_SPEED_100G RTE_BIT32(14) /**< 100 Gbps */ >>>>>> -#define RTE_ETH_LINK_SPEED_200G RTE_BIT32(15) /**< 200 Gbps */ >>>>>> -#define RTE_ETH_LINK_SPEED_400G RTE_BIT32(16) /**< 400 Gbps */ >>>>>> +#define RTE_ETH_LINK_SPEED_10G RTE_BIT32(8) /**< 10 Gbps */ >>>>>> +#define RTE_ETH_LINK_SPEED_20G RTE_BIT32(9) /**< 20 Gbps 2lanes */ >>>>>> +#define RTE_ETH_LINK_SPEED_25G RTE_BIT32(10) /**< 25 Gbps */ >>>>>> +#define RTE_ETH_LINK_SPEED_40G RTE_BIT32(11) /**< 40 Gbps 4lanes */ >>>>>> +#define RTE_ETH_LINK_SPEED_50G RTE_BIT32(12) /**< 50 Gbps */ >>>>>> +#define RTE_ETH_LINK_SPEED_56G RTE_BIT32(13) /**< 56 Gbps 4lanes */ >>>>>> +#define RTE_ETH_LINK_SPEED_100G RTE_BIT32(14) /**< 100 Gbps */ >>>>>> +#define RTE_ETH_LINK_SPEED_200G RTE_BIT32(15) /**< 200 Gbps 4lanes */ >>>>>> +#define RTE_ETH_LINK_SPEED_400G RTE_BIT32(16) /**< 400 Gbps 4lanes */ >>>>>> +#define RTE_ETH_LINK_SPEED_10G_4LANES RTE_BIT32(17) /**< 10 Gbps 4lanes */ >>>>>> +#define RTE_ETH_LINK_SPEED_50G_2LANES RTE_BIT32(18) /**< 50 Gbps 2 lanes */ >>>>>> +#define RTE_ETH_LINK_SPEED_100G_2LANES RTE_BIT32(19) /**< 100 Gbps 2 lanes */ >>>>>> +#define RTE_ETH_LINK_SPEED_100G_4LANES RTE_BIT32(20) /**< 100 Gbps 4lanes */ >>>>>> +#define RTE_ETH_LINK_SPEED_200G_2LANES RTE_BIT32(21) /**< 200 Gbps 2lanes */ >>>>>> +#define RTE_ETH_LINK_SPEED_400G_8LANES RTE_BIT32(22) /**< 400 Gbps 8lanes */ >>>>> I don't think it is a good idea to make this more complex. >>>>> It brings nothing as far as I can see, compared to having speed and lanes separated. >>>>> Can we have lanes information a separate value? no need for bitmask. >>>>> >>>> Hi,Thomas, Ajit, roretzla, damodharam >>>> >>>> I also considered the option at the beginning of the design. >>>> But this option is not used due to the following reasons: >>>> 1. For the user, ethtool couples speed and lanes. >>>> The result of querying the NIC capability is as follows: >>>> Supported link modes: >>>> 100000baseSR4/Full >>>> 100000baseSR2/Full >>>> The NIC capability is configured as follows: >>>> ethtool -s eth1 speed 100000 lanes 4 autoneg off >>>> ethtool -s eth1 speed 100000 lanes 2 autoneg off >>>> >>>> Therefore, users are more accustomed to the coupling of speed and lanes. >>>> >>>> 2. For the PHY, When the physical layer capability is configured through the MDIO, >>>> the speed and lanes are also coupled. >>>> For example: >>>> Table 45–7—PMA/PMD control 2 register bit definitions[1] >>>> PMA/PMD type selection >>>> 1 0 0 1 0 1 0 = 100GBASE-SR2 PMA/PMD >>>> 0 1 0 1 1 1 1 = 100GBASE-SR4 PMA/PMD >>>> >>>> Therefore, coupling speeds and lanes is easier to understand. >>>> And it is easier for the driver to report the support lanes. >>>> >>>> In addition, the code implementation is compatible with the old version. >>>> When the driver does not support the lanes setting, the code does not need to be modified. >>>> >>>> So I think the speed and lanes coupling is better. >>> I don't think so. >>> You are mixing hardware implementation, user tool, and API. >>> Having a separate and simple API is cleaner and not more difficult to handle >>> in some get/set style functions. >> Having a separate and simple API is cleaner. It's good. >> But supported lane capabilities have a lot to do with the specified >> speed. This is determined by releated specification. >> If we add a separate API for speed lanes, it probably is hard to check >> the validity of the configuration for speed and lanes. >> And the setting lane API sepparated from speed is not good for >> uniforming all PMD's behavior in ethdev layer. > Please let's be more specific. > There are 3 needs: > - set PHY lane config > - get PHY lane config > - get PHY lane capabilities IMO, this lane capabilities should be reported based on supported speed capabilities. > > There is no problem providing a function to get the number of PHY lanes. > It is possible to set PHY lanes number after defining a fixed speed. yes it's ok. > >> The patch[1] is an example for this separate API. >> I think it is not very good. It cannot tell user and PMD the follow points: >> 1) user don't know what lanes should or can be set for a specified speed >> on one NIC. > This is about capabilities. > Can we say a HW will support a maximum number of PHY lanes in general? > We may need to associate the maximum speed per lane? > Do we really need to associate PHY lane and PHY speed numbers for capabilities? Personally, it should contain the below releationship at least. speed 10G  --> 1lane | 4lane speed 100G  --> 2lane | 4lane > Example: if a HW supports 100G-4-lanes and 200G-2-lanes, > may we assume it is also supporting 200G-4-lanes? I think we cannot assume that NIC also support 200G-4-lanes. Beause it has a lot to do with HW design. > >> 2) how should PMD do for a supported lanes in their HW? > I don't understand this question. Please rephrase. I mean that PMD don't know set how many lanes when the lanes from user is not supported on a fixed speed by PMD. So ethdev layer should limit the avaiable lane number based on a fixed speed. > >> Anyway, if we add setting speed lanes feature, we must report and set >> speed and lanes capabilities for user well. >> otherwise, user will be more confused. > Well is not necessarily exposing all raw combinations as ethtool does. Agreed. > >> [1] https://patchwork.dpdk.org/project/dpdk/list/?series=31606 > > > .