Re: [dpdk-dev] [PATCH v2 1/2] Added ETH_SPEED_CAP bitmap in rte_eth_dev_info

[Thomas Monjalon <thomas.monjalon@6wind.com>]

2015-06-08 10:50, Marc Sune:
> On 29/05/15 20:23, Thomas Monjalon wrote:
> > 2015-05-27 11:15, Marc Sune:
> >> On 27/05/15 06:02, Thomas Monjalon wrote:
> >>>> +#define ETH_SPEED_CAP_10M_HD	(1 << 0)  /*< 10 Mbps half-duplex> */
> >>>> +#define ETH_SPEED_CAP_10M_FD	(1 << 1)  /*< 10 Mbps full-duplex> */
> >>>> +#define ETH_SPEED_CAP_100M_HD	(1 << 2)  /*< 100 Mbps half-duplex> */
> >>>> +#define ETH_SPEED_CAP_100M_FD	(1 << 3)  /*< 100 Mbps full-duplex> */
> >>>> +#define ETH_SPEED_CAP_1G	(1 << 4)  /*< 1 Gbps > */
> >>>> +#define ETH_SPEED_CAP_2_5G	(1 << 5)  /*< 2.5 Gbps > */
> >>>> +#define ETH_SPEED_CAP_5G	(1 << 6)  /*< 5 Gbps > */
> >>>> +#define ETH_SPEED_CAP_10G	(1 << 7)  /*< 10 Mbps > */
> >>>> +#define ETH_SPEED_CAP_20G	(1 << 8)  /*< 20 Gbps > */
> >>>> +#define ETH_SPEED_CAP_25G	(1 << 9)  /*< 25 Gbps > */
> >>>> +#define ETH_SPEED_CAP_40G	(1 << 10)  /*< 40 Gbps > */
> >>>> +#define ETH_SPEED_CAP_50G	(1 << 11)  /*< 50 Gbps > */
> >>>> +#define ETH_SPEED_CAP_56G	(1 << 12)  /*< 56 Gbps > */
> >>>> +#define ETH_SPEED_CAP_100G	(1 << 13)  /*< 100 Gbps > */
> >>> We should note that rte_eth_link is using ETH_LINK_SPEED_* constants
> >>> which are not some bitmaps so we have to create these new constants.
> >> Yes, I can add that to the patch description (1/2).
> >>
> >>> Furthermore, rte_eth_link.link_speed is an uint16_t so it is limited
> >>> to 40G. Should we use some constant bitmaps here also?
> >> I also thought about converting link_speed into a bitmap to unify the
> >> constants before starting the patch (there is redundancy), but I wanted
> >> to be minimally invasive; changing link to a bitmap can break existing apps.
> >>
> >> I can also merge them if we think is a better idea.
> > Maybe. Someone against this idea?
> 
> Me. I tried implementing this unified speed constantss, but the problem 
> is that for the capabilities full-duplex/half-duplex speeds are unrolled 
> (e.g. 100M_HD/100_FD). There is no generic 100M to set a specific speed, 

Or we can define ETH_SPEED_CAP_100M and ETH_SPEED_CAP_100M_FD.
Is it possible to have a NIC doing 100M_FD but not 100M_HD?

> so if you want a fiex speed and duplex auto-negociation witht the 
> current set of constants, it would look weird; e.g. 
> link_speed=ETH_SPEED_100M_HD and then set 
> link_duplex=ETH_LINK_AUTONEG_DUPLEX):
> 
>   232 struct rte_eth_link {
>   233         uint16_t link_speed;      /**< ETH_LINK_SPEED_[10, 100, 
> 1000, 10000] */
>   234         uint16_t link_duplex;     /**< ETH_LINK_[HALF_DUPLEX, 
> FULL_DUPLEX] */
>   235         uint8_t  link_status : 1; /**< 1 -> link up, 0 -> link 
> down */
>   236 }__attribute__((aligned(8)));     /**< aligned for atomic64 
> read/write */
> 
> There is another minor point, which is when setting the speed in 
> rte_eth_conf:
> 
>   840 struct rte_eth_conf {
>   841         uint16_t link_speed;
>   842         /**< ETH_LINK_SPEED_10[0|00|000], or 0 for autonegotation */
> 
> 0 is used for speed auto-negociation, but 0 is also used in the 
> capabilities bitmap to indicate no PHY_MEDIA (virtual interface). I 
> would have to define something like:
> 
> 906 #define ETH_SPEED_NOT_PHY   (0)  /*< No phy media > */
> 907 #define ETH_SPEED_AUTONEG   (0)  /*< Autonegociate speed > */

Or something like SPEED_UNDEFINED

> And use (only) NOT_PHY for a capabilities and _AUTONEG for rte_eth_conf.
> 
> The options I see:
> 
> a) add to the the list of the current speeds generic 10M/100M/1G speeds 
> without HD/FD, and just use these speeds in rte_eth_conf.
> b) leave them separated.
> 
> I would vote for b), since the a) is not completely clean. 
> Opinions&other alternatives welcome.
> 
> Marc