Re: [dpdk-dev] [PATCH v5 3/4] ethdev: redesign link speed config API

["Nélio Laranjeiro" <nelio.laranjeiro@6wind.com>]

Hi Marc,

On Sun, Oct 04, 2015 at 11:12:46PM +0200, Marc Sune wrote:
>[...]
>  /**
> + * Device supported speeds bitmap flags
> + */
> +#define ETH_LINK_SPEED_AUTONEG		(0 << 0)  /*< Autonegociate (all speeds)  */
> +#define ETH_LINK_SPEED_NO_AUTONEG	(1 << 0)  /*< Disable autoneg (fixed speed)  */
> +#define ETH_LINK_SPEED_10M_HD		(1 << 1)  /*< 10 Mbps half-duplex */
> +#define ETH_LINK_SPEED_10M		(1 << 2)  /*< 10 Mbps full-duplex */
> +#define ETH_LINK_SPEED_100M_HD		(1 << 3)  /*< 100 Mbps half-duplex */
> +#define ETH_LINK_SPEED_100M		(1 << 4)  /*< 100 Mbps full-duplex */
> +#define ETH_LINK_SPEED_1G		(1 << 5)  /*< 1 Gbps */
> +#define ETH_LINK_SPEED_2_5G		(1 << 6)  /*< 2.5 Gbps */
> +#define ETH_LINK_SPEED_5G		(1 << 7)  /*< 5 Gbps */
> +#define ETH_LINK_SPEED_10G		(1 << 8)  /*< 10 Mbps */
> +#define ETH_LINK_SPEED_20G		(1 << 9)  /*< 20 Gbps */
> +#define ETH_LINK_SPEED_25G		(1 << 10)  /*< 25 Gbps */
> +#define ETH_LINK_SPEED_40G		(1 << 11)  /*< 40 Gbps */
> +#define ETH_LINK_SPEED_50G		(1 << 12)  /*< 50 Gbps */
> +#define ETH_LINK_SPEED_56G		(1 << 13)  /*< 56 Gbps */
> +#define ETH_LINK_SPEED_100G		(1 << 14)  /*< 100 Gbps */
> +
> +/**
> + * Ethernet numeric link speeds in Mbps
> + */
> +#define ETH_SPEED_NUM_NONE	0      /*< Not defined */
> +#define ETH_SPEED_NUM_10M	10     /*< 10 Mbps */
> +#define ETH_SPEED_NUM_100M	100    /*< 100 Mbps */
> +#define ETH_SPEED_NUM_1G	1000   /*< 1 Gbps */
> +#define ETH_SPEED_NUM_2_5G	2500   /*< 2.5 Gbps */
> +#define ETH_SPEED_NUM_5G	5000   /*< 5 Gbps */
> +#define ETH_SPEED_NUM_10G	10000  /*< 10 Mbps */
> +#define ETH_SPEED_NUM_20G	20000  /*< 20 Gbps */
> +#define ETH_SPEED_NUM_25G	25000  /*< 25 Gbps */
> +#define ETH_SPEED_NUM_40G	40000  /*< 40 Gbps */
> +#define ETH_SPEED_NUM_50G	50000  /*< 50 Gbps */
> +#define ETH_SPEED_NUM_56G	56000  /*< 56 Gbps */
> +#define ETH_SPEED_NUM_100G	100000 /*< 100 Gbps */
> +
> +/**
>   * A structure used to retrieve link-level information of an Ethernet port.
>   */
>  struct rte_eth_link {
> -	uint16_t link_speed;      /**< ETH_LINK_SPEED_[10, 100, 1000, 10000] */
> -	uint16_t link_duplex;     /**< ETH_LINK_[HALF_DUPLEX, FULL_DUPLEX] */
> -	uint8_t  link_status : 1; /**< 1 -> link up, 0 -> link down */
> -}__attribute__((aligned(8)));     /**< aligned for atomic64 read/write */
> -
> -#define ETH_LINK_SPEED_AUTONEG  0       /**< Auto-negotiate link speed. */
> -#define ETH_LINK_SPEED_10       10      /**< 10 megabits/second. */
> -#define ETH_LINK_SPEED_100      100     /**< 100 megabits/second. */
> -#define ETH_LINK_SPEED_1000     1000    /**< 1 gigabits/second. */
> -#define ETH_LINK_SPEED_10000    10000   /**< 10 gigabits/second. */
> -#define ETH_LINK_SPEED_10G      10000   /**< alias of 10 gigabits/second. */
> -#define ETH_LINK_SPEED_20G      20000   /**< 20 gigabits/second. */
> -#define ETH_LINK_SPEED_40G      40000   /**< 40 gigabits/second. */
> +	uint32_t link_speed;       /**< Link speed (ETH_SPEED_NUM_) */
> +	uint16_t link_duplex;      /**< 1 -> full duplex, 0 -> half duplex */
> +	uint8_t link_autoneg : 1;  /**< 1 -> link speed has been autoneg */
> +	uint8_t link_status  : 1;  /**< 1 -> link up, 0 -> link down */
> +} __attribute__((aligned(8)));      /**< aligned for atomic64 read/write */
>[...]

Pretty good.  One question, why did you not merge link_duplex, autoneg,
and status like:

	struct rte_eth_link {
		uint32_t link_speed;
		uint32_t link_duplex:1;
		uint32_t link_autoneg:1;
		uint32_t link_status:1;
	};

is it really useful to keep a uint16_t for the duplex alone?

Another point, the comment about link_duplex field should point to the
defines you have changed i.e. ETH_LINK_HALF_DUPLEX, ETH_LINK_FULL_DUPLEX.

Regards,

-- 
Nélio Laranjeiro
6WIND