On 02/10/2017 08:42 AM, Claudiu Manoil wrote:
> Commit: f62265b "at803x: double check SGMII side autoneg"
> introduced a regression for the p1010rdb board which has
> two of the ethernet controllers (eTSEC) connected through
> SGMII links to external Atheros SGMII AR8033 PHYs.
> The issue consists in a dead link for these ports, and is
> 100% reproducible on kernel 4.9 (and later):
>
> root@p1010rdb-pb:~# ifconfig eth2 172.16.1.1
> [ 203.274263] IPv6: ADDRCONF(NETDEV_UP): eth2: link is not ready
> root@p1010rdb-pb:~# [ 206.408255] 803x_aneg_done: SGMII link is not ok
>
> root@p1010rdb-pb:~# ethtool eth2
> Settings for eth2:
> Supported ports: [ MII ]
> Supported link modes: 10baseT/Half 10baseT/Full
> 100baseT/Half 100baseT/Full
> 1000baseT/Full
> Supported pause frame use: Symmetric Receive-only
> Supports auto-negotiation: Yes
> Advertised link modes: 10baseT/Half 10baseT/Full
> 100baseT/Half 100baseT/Full
> 1000baseT/Full
> Advertised pause frame use: No
> Advertised auto-negotiation: Yes
> Link partner advertised link modes: 10baseT/Half 10baseT/Full
> 100baseT/Half 100baseT/Full
> 1000baseT/Half 1000baseT/Full
> Link partner advertised pause frame use: Symmetric Receive-only
> Link partner advertised auto-negotiation: Yes
> Speed: 1000Mb/s
> Duplex: Full
> Port: MII
> PHYAD: 2
> Transceiver: internal
> Auto-negotiation: on
> Supports Wake-on: g
> Wake-on: d
> Current message level: 0x0000003f (63)
> drv probe link timer ifdown ifup
> Link detected: no
>
> Insuring up to 100 usecs for the SGMII link side AN to complete
> proves to be enough to have a working SGMII link, for this board.
> The need for a delay for the SGMII link side may be explained by
> the fact that there are two levels of auto-negotiation (AN) for a
> SGMII link. First the PHY autonegotiates the link parameters w/
> its link partner over the copper link. In the second stage, the
> AN results are then passed to the eTSEC MAC over the SGMII link
> using the Clause 37 auto-negotiation functionality. While the
> aneg_done() hook is called by the phylib state machine to check
> for the completion of the 1st stage AN of the external PHY,
> there's no mechanism to insure proper AN completion of the internal
> SGMII link (which is actually handled on the eTSEC side by a
> "internal PHY", called TBI).
>
> Fixes: f62265b "at803x: double check SGMII side autoneg"
>
> Signed-off-by: Claudiu Manoil <claudiu.man...@nxp.com>
> ---
> drivers/net/phy/at803x.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/phy/at803x.c b/drivers/net/phy/at803x.c
> index a52b560..55fa7c4 100644
> --- a/drivers/net/phy/at803x.c
> +++ b/drivers/net/phy/at803x.c
> @@ -366,6 +366,7 @@ static void at803x_link_change_notify(struct phy_device
> *phydev)
> static int at803x_aneg_done(struct phy_device *phydev)
> {
> int ccr;
> + int timeout = 100; /* usecs */
unsigned int, and use reverse christmas tree declarations, order from
longest variable to shortest.
--
Florian
