[PATCH RFC net-next v2 11/19] net: stmmac: do not require snps,ps-speed for SGMII

[Russell King (Oracle)]

SGMII mode does not require port-speed to be specified; this only
switches SGMII to use the MAC configuration register speed settings
and the actual value is irrelevant when the link comes up.

As it seems the intention was to support "reverse SGMII" with this
setting, but the code didn't actually configure that due to a typo,
the warning and bad DT binding documentation has led people to
specify snps,ps-speed in their DT files inappropriately.

If mac_port_sel_speed is zero, then don't complain that the speed
is invalid, as this means we're using "normal" SGMII.

Signed-off-by: Russell King (Oracle) <rmk+kernel at armlinux.org.uk>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 60fcf3feac31..e2d9c08aace8 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1101,6 +1101,8 @@ static void stmmac_check_pcs_mode(struct stmmac_priv *priv)
 
 		default:
 			dev_warn(priv->device, "invalid port speed\n");
+			fallthrough;
+		case 0:
 			priv->hw->reverse_sgmii_enable = false;
 			break;
 		}
-- 
2.47.3