[PATCH v3 1/1 net-next] net: fec: enable pause frame to improve rx prefomance for 1G network

[Frank Li]

2013/1/24 Ben Hutchings <bhutchings at solarflare.com>:
> On Thu, 2013-01-17 at 10:55 +0800, Frank Li wrote:
>> The limition of imx6 internal bus cause fec can't achieve 1G perfomance.
>> There will be many packages lost because FIFO over run.
>>
>> This patch enable pause frame flow control.
> [...]
>> --- a/drivers/net/ethernet/freescale/fec.c
>> +++ b/drivers/net/ethernet/freescale/fec.c
> [...]
>> +static int fec_enet_set_pauseparam(struct net_device *ndev,
>> +                                struct ethtool_pauseparam *pause)
>> +{
>> +     struct fec_enet_private *fep = netdev_priv(ndev);
>> +
>> +     if (pause->tx_pause != pause->rx_pause) {
>> +             netdev_info(ndev,
>> +                     "hardware only support enable/disable both tx and rx");
>> +             return -EINVAL;
>> +     }
>> +
>> +     fep->pause_flag = 0;
>> +
>> +     /* tx pause must be same as rx pause */
>> +     fep->pause_flag |= pause->rx_pause ? FEC_PAUSE_FLAG_ENABLE : 0;
>> +     fep->pause_flag |= pause->autoneg ? FEC_PAUSE_FLAG_AUTONEG : 0;
>> +
>> +     if (pause->rx_pause || pause->autoneg) {
>> +             fep->phy_dev->supported |= ADVERTISED_Pause;
>> +             fep->phy_dev->advertising |= ADVERTISED_Pause;
>> +     } else {
>> +             fep->phy_dev->supported &= ~ADVERTISED_Pause;
>> +             fep->phy_dev->advertising &= ~ADVERTISED_Pause;
>> +     }
> [...]
>
> Why is this changing the supported flags, i.e. device capabilities?  You
> need to leave those flags alone and reject an attempt to enable pause
> frames on a device that doesn't support them.

I go through phylib, I have not found good place set ADVERTISED_Pause
capabilities.
genphy_config_init never check Pause capabilities.

>
> Ben.
>
> --
> Ben Hutchings, Staff Engineer, Solarflare
> Not speaking for my employer; that's the marketing department's job.
> They asked us to note that Solarflare product names are trademarked.
>