net: stmmac: Drop TBI/RTBI PCS flags

First of all the flags are never set by any of the driver parts. If nobody
have them set then the respective statements will always have the same
result. Thus the statements can be simplified or even dropped with no risk
to break things.

Secondly shall any of the TBI or RTBI flag is set the MDIO-bus
registration will be bypassed. Why? It really seems weird. It's perfectly
fine to have a TBI/RTBI-capable PHY configured over the MDIO bus
interface.

Based on the notes above the TBI/RTBI PCS flags can be freely dropped thus
simplifying the driver code.
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Link: https://lore.kernel.org/r/E1sCErK-00EOPf-EP@rmk-PC.armlinux.org.ukSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/stmicro/stmmac/common.h

@@ -271,8 +271,6 @@ struct stmmac_safety_stats {
 /* PCS defines */
 #define STMMAC_PCS_RGMII	(1 << 0)
 #define STMMAC_PCS_SGMII	(1 << 1)
-#define STMMAC_PCS_TBI		(1 << 2)
-#define STMMAC_PCS_RTBI		(1 << 3)
 
 #define SF_DMA_MODE 1		/* DMA STORE-AND-FORWARD Operation Mode */
 

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -471,13 +471,6 @@ bool stmmac_eee_init(struct stmmac_priv *priv)
 {
 	int eee_tw_timer = priv->eee_tw_timer;
 
-	/* Using PCS we cannot dial with the phy registers at this stage
-	 * so we do not support extra feature like EEE.
-	 */
-	if (priv->hw->pcs == STMMAC_PCS_TBI ||
-	    priv->hw->pcs == STMMAC_PCS_RTBI)
-		return false;
-
 	/* Check if MAC core supports the EEE feature. */
 	if (!priv->dma_cap.eee)
 		return false;
@@ -3953,9 +3946,7 @@ static int __stmmac_open(struct net_device *dev,
 	if (ret < 0)
 		return ret;
 
-	if (priv->hw->pcs != STMMAC_PCS_TBI &&
-	    priv->hw->pcs != STMMAC_PCS_RTBI &&
-	    (!priv->hw->xpcs ||
+	if ((!priv->hw->xpcs ||
 	     xpcs_get_an_mode(priv->hw->xpcs, mode) != DW_AN_C73)) {
 		ret = stmmac_init_phy(dev);
 		if (ret) {
@@ -7739,16 +7730,12 @@ int stmmac_dvr_probe(struct device *device,
 	if (!pm_runtime_enabled(device))
 		pm_runtime_enable(device);
 
-	if (priv->hw->pcs != STMMAC_PCS_TBI &&
-	    priv->hw->pcs != STMMAC_PCS_RTBI) {
-		/* MDIO bus Registration */
-		ret = stmmac_mdio_register(ndev);
-		if (ret < 0) {
-			dev_err_probe(priv->device, ret,
-				      "%s: MDIO bus (id: %d) registration failed\n",
-				      __func__, priv->plat->bus_id);
-			goto error_mdio_register;
-		}
+	ret = stmmac_mdio_register(ndev);
+	if (ret < 0) {
+		dev_err_probe(priv->device, ret,
+			      "MDIO bus (id: %d) registration failed\n",
+			      priv->plat->bus_id);
+		goto error_mdio_register;
 	}
 
 	if (priv->plat->speed_mode_2500)
@@ -7790,9 +7777,7 @@ int stmmac_dvr_probe(struct device *device,
 error_phy_setup:
 	stmmac_pcs_clean(ndev);
 error_pcs_setup:
-	if (priv->hw->pcs != STMMAC_PCS_TBI &&
-	    priv->hw->pcs != STMMAC_PCS_RTBI)
-		stmmac_mdio_unregister(ndev);
+	stmmac_mdio_unregister(ndev);
 error_mdio_register:
 	stmmac_napi_del(ndev);
 error_hw_init:
@@ -7833,10 +7818,8 @@ void stmmac_dvr_remove(struct device *dev)
 	reset_control_assert(priv->plat->stmmac_ahb_rst);
 
 	stmmac_pcs_clean(ndev);
+	stmmac_mdio_unregister(ndev);
 
-	if (priv->hw->pcs != STMMAC_PCS_TBI &&
-	    priv->hw->pcs != STMMAC_PCS_RTBI)
-		stmmac_mdio_unregister(ndev);
 	destroy_workqueue(priv->wq);
 	mutex_destroy(&priv->lock);
 	bitmap_free(priv->af_xdp_zc_qps);