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

[Marc Sune <marc.sune@bisdn.de>]

On 11/06/15 11:08, Thomas Monjalon wrote:
> 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?

Did not check in detail, but I guess this is mostly legacy NICs, not 
supported by DPDK anyway, and that is safe to assume 10M/100M meaning 
supports both HD/FD.

>
>> 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

Ok. I will prepare the patch and circulate a v3.

After briefly chatting offline with Thomas, it seems I was not clearly 
stating in my original v1 that this patch is targeting DPDK v2.2, due to 
ABI(and API) issues.

It is, and so I will hold v3 until 2.2 window starts, to make it more clear.

thanks
Marc
>
>> 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