net: dsa: sja1105: ensure phylink_replay_link_end() will not be missed

Most errors that can occur in sja1105_static_config_reload() are fatal
(example: fail to communicate with hardware), but not all are.

For example, sja1105_static_config_upload() -> kcalloc() may fail, and
if that happens, we have called phylink_replay_link_begin() but never
phylink_replay_link_end().

Under that circumstance, all port phylink instances are left in a state
where the resolver is stopped with the PHYLINK_DISABLE_REPLAY bit set.
We have effectively disabled link management with no way to recover from
this condition.

Avoid that situation by ensuring phylink_replay_link_begin() is always
paired with phylink_replay_link_end(), regardless of whether we faced
any errors during switch reset, configuration reload and general state
reload.

Fixes: 0b2edc5 ("net: dsa: sja1105: let phylink help with the replay of link callbacks")
Signed-off-by: Vladimir Oltean <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: vladimiroltean

drivers/net/dsa/sja1105/sja1105_main.c

@@ -2341,10 +2341,11 @@ int sja1105_static_config_reload(struct sja1105_private *priv,
 
 	rc = sja1105_reload_cbs(priv);
 
+out:
 	dsa_switch_for_each_available_port(dp, ds)
 		if (dp->pl)
 			phylink_replay_link_end(dp->pl);
-out:
+
 	mutex_unlock(&priv->mgmt_lock);
 	mutex_unlock(&priv->fdb_lock);