RE: [Intel-wired-lan] [PATCH net-next 1/2] igb: detect M88E1112 100BASE-FX SGMII mode

[Rinitha, SX]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@xxxxxxxxxx> On Behalf Of Pawel Dembicki
> Sent: 18 July 2026 22:22
> To: netdev@xxxxxxxxxxxxxxx
> Cc: Pawel Dembicki <paweldembicki@xxxxxxxxx>; Nguyen, Anthony L <anthony.l.nguyen@xxxxxxxxx>; Kitszel, Przemyslaw <przemyslaw.kitszel@xxxxxxxxx>; Andrew Lunn <andrew+netdev@xxxxxxx>; David S. Miller <davem@xxxxxxxxxxxxx>; Eric Dumazet <edumazet@xxxxxxxxxx>; Jakub Kicinski <kuba@xxxxxxxxxx>; Paolo Abeni <pabeni@xxxxxxxxxx>; intel-wired-lan@xxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: [Intel-wired-lan] [PATCH net-next 1/2] igb: detect M88E1112 100BASE-FX SGMII mode
>
> The M88E1112 can be strapped or EEPROM-configured to bridge SGMII to 100BASE-FX. In this mode the driver still needs the SGMII PHY register access path to identify the external PHY, but the MAC link setup must follow the SERDES media path rather than copper setup.
>
> Decode the M88E1112 MAC Control 1 mode field and switch the I210 media type and physical interface setup callback when the PHY reports 100BASE-FX mode.
>
> The driver only observes the Marvell mode. It does not program the
> 88E1112 registers or its EEPROM. The board must configure it through firmware or straps before probe.
>
> Assisted-by: Codex:GPT-5
> Signed-off-by: Pawel Dembicki <paweldembicki@xxxxxxxxx>
> ---
> drivers/net/ethernet/intel/igb/e1000_82575.c   | 12 +++++++++++-
> drivers/net/ethernet/intel/igb/e1000_defines.h |  1 +
> 2 files changed, 12 insertions(+), 1 deletion(-)
>

Tested-by: Rinitha S <sx.rinitha@xxxxxxxxx> (A Contingent worker at Intel)