[PATCH net-next v12 08/18] net: ethernet: mtk_eth_soc: fix 1000Base-X and 2500Base-X modes

[Daniel Golle <daniel@makrotopia.org>]

After conversion to phylink_pcs the 1000Base-X and 2500Base-X modes
would work only after `ethtool -s eth1 autoneg off`.
As ethtool autoneg and the ETHTOOL_LINK_MODE_Autoneg_BIT is supposed
to control auto-negotiation on the external interface it doesn't make
much sense to use it to control on-board SGMII auto-negotiation between
MAC and PHY.
Set correct values to really only enable SGMII auto-negotiation when
actually operating in SGMII mode. For 1000Base-X and 2500Base-X mode,
enable remote-fault detection only if in-band-status is enabled.
This fixes using 1000Base-X and 2500Base-X SFPs on the BananaPi R3
board and also makes it possible to use interface-mode-switching PHYs
operating in either SGMII mode for 10M/100M/1000M or in 2500Base-X for
2500M mode on other boards.

Fixes: 14a44ab0330d ("net: mtk_eth_soc: partially convert to phylink_pcs")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
 drivers/net/ethernet/mediatek/mtk_sgmii.c | 24 +++++------------------
 1 file changed, 5 insertions(+), 19 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_sgmii.c b/drivers/net/ethernet/mediatek/mtk_sgmii.c
index 61bd9986466a..58d8cb3aa7f4 100644
--- a/drivers/net/ethernet/mediatek/mtk_sgmii.c
+++ b/drivers/net/ethernet/mediatek/mtk_sgmii.c
@@ -38,9 +38,9 @@ static int mtk_pcs_config(struct phylink_pcs *pcs, unsigned int mode,
 			  const unsigned long *advertising,
 			  bool permit_pause_to_mac)
 {
-	bool mode_changed = false, changed, use_an;
 	struct mtk_pcs *mpcs = pcs_to_mtk_pcs(pcs);
-	unsigned int rgc3, sgm_mode, bmcr;
+	unsigned int rgc3, sgm_mode = 0, bmcr = 0;
+	bool mode_changed = false, changed;
 	int advertise, link_timer;
 
 	advertise = phylink_mii_c22_pcs_encode_advertisement(interface,
@@ -55,27 +55,13 @@ static int mtk_pcs_config(struct phylink_pcs *pcs, unsigned int mode,
 	if (interface == PHY_INTERFACE_MODE_SGMII) {
 		sgm_mode = SGMII_IF_MODE_SGMII;
 		if (phylink_autoneg_inband(mode)) {
+			bmcr = SGMII_AN_ENABLE;
 			sgm_mode |= SGMII_REMOTE_FAULT_DIS |
 				    SGMII_SPEED_DUPLEX_AN;
-			use_an = true;
-		} else {
-			use_an = false;
 		}
-	} else if (phylink_autoneg_inband(mode)) {
-		/* 1000base-X or 2500base-X autoneg */
-		sgm_mode = SGMII_REMOTE_FAULT_DIS;
-		use_an = linkmode_test_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
-					   advertising);
-	} else {
+	} else if (!phylink_autoneg_inband(mode)) {
 		/* 1000base-X or 2500base-X without autoneg */
-		sgm_mode = 0;
-		use_an = false;
-	}
-
-	if (use_an) {
-		bmcr = SGMII_AN_ENABLE;
-	} else {
-		bmcr = 0;
+		sgm_mode = SGMII_REMOTE_FAULT_DIS;
 	}
 
 	if (mpcs->interface != interface) {
-- 
2.39.2