[PATCH net v2 1/3] net: stmmac: propagate platform mac_finish errors

[Thomas Karpiniec]

From: Thomas Karpiniec <tom at wendy.sh>

stmmac_mac_finish() discards the platform callback's return value and
always reports success to phylink. For example, the Qualcomm ETHQOS
callback can return an error from phy_set_mode_ext() if SerDes
configuration fails. Phylink then treats the interface as successfully
configured and can report carrier even though the SerDes is not ready.

Return the platform callback's result so that phylink can report the
failure and keep the link down until a subsequent configuration succeeds.
Keep returning zero when no platform callback is installed.

Fixes: e654cfc718d4 ("net: stmmac: configure SerDes on mac_finish")
Cc: stable at vger.kernel.org
Assisted-by: LLM sparse
Signed-off-by: Thomas Karpiniec <tom at wendy.sh>
Acked-by: Mohd Ayaan Anwar <mohd.anwar at oss.qualcomm.com>
Reviewed-by: Maxime Chevallier <maxime.chevallier at bootlin.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 1fb5f804ea23..1350e92943ac 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1048,8 +1048,8 @@ static int stmmac_mac_finish(struct phylink_config *config, unsigned int mode,
 	struct stmmac_priv *priv = netdev_priv(ndev);
 
 	if (priv->plat->mac_finish)
-		priv->plat->mac_finish(ndev, priv->plat->bsp_priv, mode,
-				       interface);
+		return priv->plat->mac_finish(ndev, priv->plat->bsp_priv, mode,
+					     interface);
 
 	return 0;
 }
-- 
2.54.0 (Apple Git-157)