On Tue, Mar 26, 2024 at 6:47 AM Ajit Khaparde wrote: > > On Tue, Mar 26, 2024 at 4:15 AM lihuisong (C) wrote: > > > > > > 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. > > ethdev layer has generally been opaque. We should keep it that way. I mis-typed. %s/opaque/transparent > The PMD should know what the HW supports. > So it should show the capabilities correctly. Right? > And if the user provides incorrect settings, it should reject it. > > > > > > >> 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 > > > > > > > > > .