[PATCH net-next v15 1/9] net: phy: aquantia: fix system interface type not updated in forced mode

[Bartosz Golaszewski]

On Thu, 1 Oct 2026 01:33:34 +0200, Jakub Kicinski <kuba at kernel.org> said:
> On Wed, 23 Sep 2026 17:14:35 +0200 Bartosz Golaszewski wrote:
>> aqr_gen1_read_status() decodes the MDIO_PHYXS_VEND_IF_STATUS register
>> to determine which SerDes interface the PHY is currently using on its
>> system side and stores the result in phydev->interface. phylink relies
>> on this value to configure the MAC.
>>
>> The autoneg == AUTONEG_DISABLE check is not correct:
>> MDIO_PHYXS_VEND_IF_STATUS is set by the PHY firmware based on the
>> negotiated link speed, not based on whether autoneg was used to reach
>> it. When the link comes up at 1G in forced mode, the register correctly
>> reads SGMII, but the early return prevents phydev->interface from being
>> updated. It stays at whatever value it held before (typically 2500BASE-X
>> from the initial autoneg run), so phylink configures the MAC for the
>> wrong interface and the link cannot come up.
>>
>> Remove the autoneg guard so that the system interface type is always
>> decoded when the link is up.
>>
>> Cc: stable at vger.kernel.org
>> Fixes: 110a2432c520 ("net: phy: aquantia: add downshift support")
>> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski at oss.qualcomm.com>
>
> Sounds like a real regression, is it? Should we ship it to Linus
> tomorrow so that it makes 7.3? stable + next does not compute for me
>

Yes, this is independent from the rest of the series and a small fix. It sounds
good to send it upstream ASAP.

Bart