Re: [dpdk-dev] [PATCH v11 0/8] ethdev: 100G and link speed API refactoring

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

2016-03-26 11:24, Marc:
> On 26 March 2016 at 09:08, Thomas Monjalon <thomas.monjalon@6wind.com>
> wrote:
> > 2016-03-25 22:30, Marc:
> > > From v9 to v10 patchset the values ETH_LINK_SPEED_AUTONEG and
> > ETH_LINK_SPEED_FIXED were flipped. Reverting this makes it work:
> > >
> > > marc@Beluga:~/personal/dpdk/tools$ git diff
> > > diff --git a/lib/librte_ether/rte_ethdev.h
> > b/lib/librte_ether/rte_ethdev.h
> > > index ef2502a..fb247a7 100644
> > > --- a/lib/librte_ether/rte_ethdev.h
> > > +++ b/lib/librte_ether/rte_ethdev.h
> > > @@ -244,8 +244,8 @@ struct rte_eth_stats {
> > >  /**
> > >   * Device supported speeds bitmap flags
> > >   */
> > > -#define ETH_LINK_SPEED_FIXED    (0 <<  0)  /**< Disable autoneg (fixed
> > speed) */
> > > -#define ETH_LINK_SPEED_AUTONEG  (1 <<  0)  /**< Autonegotiate (all
> > speeds) */
> > > +#define ETH_LINK_SPEED_AUTONEG  (0 <<  0)  /**< Autonegotiate (all
> > speeds) */
> > > +#define ETH_LINK_SPEED_FIXED    (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 */
> > >
> > > I think having autoneg == 0 is better. Do you agree Thomas?
> >
> > No I do not agree, because this flag is now used also for
> > rte_eth_link.link_autoneg.
> > So it is more logic to set it to 1.
> 
> Having to explicitly specify ETH_LINK_SPEED_AUTONEG in link_speeds during
> port configuration for achieving auto-negociation, which is what 98% of
> applications will use, seems anti-natural to me and breaks existing
> applications.

Yes, you're right. We have to avoid apps modifications.
By keeping autoneg the default behaviour (value 0), we avoid issues.

> The only benefit of your approach is not to have another macro #define
> ETH_LINK_AUTONEG 1, which is marginal IMHO.

Yes, you're right.
I suggest adding 2 macros for rte_eth_link.link_autoneg:
#define ETH_LINK_FIXED      0 /**< No autonegotiation. */
#define ETH_LINK_AUTONEG    1 /**< Autonegotiated. */

and keep these ones to use with rte_eth_conf.link_speeds and
rte_eth_dev_info.speed_capa:
#define ETH_LINK_SPEED_AUTONEG  (0 <<  0)  /**< Autonegotiate (all speeds) */
#define ETH_LINK_SPEED_FIXED    (1 <<  0)  /**< Disable autoneg (fixed speed) */

Opinions?