On Wed, Jul 06, 2022 at 01:26:21PM +0300, Vladimir Oltean wrote:

Hello,

On Tue, Jul 05, 2022 at 10:48:07AM +0100, Russell King (Oracle) wrote:

quoted

diff --git a/net/dsa/port.c b/net/dsa/port.c
index 35b4e1f8dc05..34487e62eb03 100644
--- a/net/dsa/port.c
+++ b/net/dsa/port.c

@@ -1525,6 +1525,7 @@ int dsa_port_phylink_create(struct dsa_port *dp)
 {
 	struct dsa_switch *ds = dp->ds;
 	phy_interface_t mode, def_mode;
+	struct device_node *phy_np;
 	int err;
 
 	/* Presence of phylink_mac_link_state or phylink_mac_an_restart is

@@ -1559,6 +1560,13 @@ int dsa_port_phylink_create(struct dsa_port *dp)
 		return PTR_ERR(dp->pl);
 	}
 
+	if (dp->type == DSA_PORT_TYPE_CPU || dp->type == DSA_PORT_TYPE_DSA) {
+		phy_np = of_parse_phandle(dp->dn, "phy-handle", 0);
+		of_node_put(phy_np);
+		if (!phy_np)
+			err = phylink_set_max_fixed_link(dp->pl);

Can we please limit phylink_set_max_link_speed() to just the CPU ports
where a fixed-link property is also missing, not just a phy-handle?
Although to be entirely correct, we can also have MLO_AN_INBAND, which
wouldn't be covered by these 2 checks and would still represent a valid
DT binding.

phylink_set_max_fixed_link() already excludes itself:

        if (pl->cfg_link_an_mode != MLO_AN_PHY || pl->phydev || pl->sfp_bus)
                return -EBUSY;

intentionally so that if there is anything specified for the port, be
that a fixed link or in-band, then phylink_set_max_fixed_link() errors
out with -EBUSY.

The only case that it can't detect is if there is a PHY that may be
added to phylink at a later time, and that is what the check above
is for.

-- 
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