On 07/02/2018 02:31 PM, Heiner Kallweit wrote:
> On 02.07.2018 23:20, Andrew Lunn wrote:
>> On Mon, Jul 02, 2018 at 09:37:08PM +0200, Heiner Kallweit wrote:
>>> Change rtl_speed_down() to use phylib.
>>>
>>> Signed-off-by: Heiner Kallweit <hkallwe...@gmail.com>
>>> ---
>>> drivers/net/ethernet/realtek/r8169.c | 33 +++++++++++++---------------
>>> 1 file changed, 15 insertions(+), 18 deletions(-)
>>>
>>> diff --git a/drivers/net/ethernet/realtek/r8169.c
>>> b/drivers/net/ethernet/realtek/r8169.c
>>> index 311321ee..807fbc75 100644
>>> --- a/drivers/net/ethernet/realtek/r8169.c
>>> +++ b/drivers/net/ethernet/realtek/r8169.c
>>> @@ -4240,6 +4240,10 @@ static void rtl8169_init_phy(struct net_device *dev,
>>> struct rtl8169_private *tp)
>>> rtl_writephy(tp, 0x0b, 0x0000); //w 0x0b 15 0 0
>>> }
>>>
>>> + /* We may have called rtl_speed_down before */
>>> + dev->phydev->advertising = dev->phydev->supported;
>>> + genphy_config_aneg(dev->phydev);
>>> +
>>> genphy_soft_reset(dev->phydev);
>>>
>>> rtl8169_set_speed(dev, AUTONEG_ENABLE, SPEED_1000, DUPLEX_FULL,
>>> @@ -4323,28 +4327,21 @@ static void rtl_init_mdio_ops(struct
>>> rtl8169_private *tp)
>>> }
>>> }
>>>
>>> +#define BASET10 (ADVERTISED_10baseT_Half |
>>> ADVERTISED_10baseT_Full)
>>> +#define BASET100 (ADVERTISED_100baseT_Half | ADVERTISED_100baseT_Full)
>>> +#define BASET1000 (ADVERTISED_1000baseT_Half | ADVERTISED_1000baseT_Full)
>>> +
>>> static void rtl_speed_down(struct rtl8169_private *tp)
>>> {
>>> - u32 adv;
>>> - int lpa;
>>> + struct phy_device *phydev = tp->dev->phydev;
>>> + u32 adv = phydev->lp_advertising & phydev->supported;
>>>
>>> - rtl_writephy(tp, 0x1f, 0x0000);
>>> - lpa = rtl_readphy(tp, MII_LPA);
>>> + if (adv & BASET10)
>>> + phydev->advertising &= ~(BASET100 | BASET1000);
>>> + else if (adv & BASET100)
>>> + phydev->advertising &= ~BASET1000;
>>>
>>> - if (lpa & (LPA_10HALF | LPA_10FULL))
>>> - adv = ADVERTISED_10baseT_Half | ADVERTISED_10baseT_Full;
>>> - else if (lpa & (LPA_100HALF | LPA_100FULL))
>>> - adv = ADVERTISED_10baseT_Half | ADVERTISED_10baseT_Full |
>>> - ADVERTISED_100baseT_Half | ADVERTISED_100baseT_Full;
>>> - else
>>> - adv = ADVERTISED_10baseT_Half | ADVERTISED_10baseT_Full |
>>> - ADVERTISED_100baseT_Half | ADVERTISED_100baseT_Full |
>>> - (tp->mii.supports_gmii ?
>>> - ADVERTISED_1000baseT_Half |
>>> - ADVERTISED_1000baseT_Full : 0);
>>> -
>>> - rtl8169_set_speed(tp->dev, AUTONEG_ENABLE, SPEED_1000, DUPLEX_FULL,
>>> - adv);
>>> + genphy_config_aneg(phydev);
>>> }
>>
>> It probably it is me being too tired, but i don't get what this is
>> doing? Changing the local advertisement based on what the remote is
>> advertising. Why?
>>
> It also took me some time to understand what this speed_down is doing.
> If we suspend and wait for a WoL packet, then we don't have to burn all
> the energy for a GBit connection. Therefore we switch to the lowest
> speed supported by chip and link partner. This is done by removing
> higher speeds from the advertised modes and restarting an autonego.
This is something that the tg3 driver also does, we should probably
consider doing this as part of a generic PHY library helpers since I was
told by several HW engineers that usually 10Mbits for WoL is much more
energy efficient.
One thing that bothers me a bit is that this should ideally be offered
as both blocking and non-blocking options, because we might want to make
sure that at the time we suspend, and we already had a link established,
we successfully re-negotiate the link with the partner. I agree that
there could be any sort of link disruption happening at any point though..
--
Florian
