Re: [PATCH net-next v2 1/2] net: phylink: unwind the PHY binding when bringup fails late

[Andrew Lunn <andrew@lunn.ch>]

On Mon, Aug 24, 2026 at 05:40:27AM +0300, Aleksei Sviridkin wrote:
> phylink_bringup_phy() records the PHY in pl->phydev before its last
> fallible step: on a MAC whose phylink ops implement LPI,
> phy_eee_rx_clock_stop() can fail with a real MDIO error. The callers
> unwind with phy_detach(), which knows nothing about pl->phydev, so a
> pointer to a PHY that is no longer attached outlives the failed
> connect.
> 
> What that costs depends on how the caller got here.
> phylink_connect_phy() and the SFP path go through
> phylink_attach_phy(), which refuses to attach while pl->phydev is set
> and turns a transient MDIO error into a permanent -EBUSY.
> phylink_fwnode_phy_connect() has no such check, so a later connect
> overwrites the stale pointer and hides the problem. A disconnect does
> not: phylink_disconnect_phy() hands that pointer to phy_disconnect(),
> and the second phy_detach() on the same PHY drops references the first
> one already released.
> 
> Clear the binding on the failure path. This is the same operation
> phylink_disconnect_phy() performs, so both now share a helper. The
> PHY-side fields are left to phy_detach(), which every caller already
> runs on this path.
> 
> Fixes: 03abf2a7c654 ("net: phylink: add EEE management")
> Signed-off-by: Aleksei Sviridkin <f@lex.la>

This should be for net, not net-next.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew