Re: [PATCH net-next v16 4/7] net: stmmac: qcom-ethqos: update phy_mode to the resolved interface in mac_finish()

[Mohd Ayaan Anwar]

On Wed, Oct 14, 2026 at 02:36:43PM +0200, Bartosz Golaszewski wrote:
> ethqos->phy_mode is read by serdes_powerup() and
> qcom_ethqos_set_sgmii_loopback() to configure the SerDes and its
> wrapper for the correct interface. It is set once at probe from the DT
> phy-mode property and never updated.
> 
> phylink resolves the actual runtime interface and passes it to the
> mac_finish() callback. On platforms that only ever operate at one speed
> these two values are always the same, but when the interface changes
> at runtime - for example switching between SGMII and 2500BASE-X - the
> stored value becomes stale. The next serdes_powerup() call, on
> a subsequent link cycle, then reinitializes the SerDes to the wrong mode.
> 
> Update ethqos->phy_mode from the interface argument in
> ethqos_mac_finish_serdes() so that it always reflects the last
> resolved interface.
> 
> With that, we now update the phy_mode to the runtime-resolved interface,
> so any subsequent resume with a 1G SGMII link skips the loopback setup
> and the DMA reset hangs. To remedy this, extend the guard to include
> PHY_INTERFACE_MODE_SGMII.
> 
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxxxxxxxx>
> ---

I am not sure but should this have a Fixes: tag?

Reviewed-by: Mohd Ayaan Anwar <mohd.anwar@xxxxxxxxxxxxxxxx>

	Ayaan