diff mbox series

[net-next,v2,1/2] net: pcs: xpcs: enable skip xPCS soft reset

Message ID 20210826235134.4051310-1-vee.khee.wong@linux.intel.com (mailing list archive)
State New, archived
Headers show
Series [net-next,v2,1/2] net: pcs: xpcs: enable skip xPCS soft reset | expand

Commit Message

Wong Vee Khee Aug. 26, 2021, 11:51 p.m. UTC 
Unlike any other platforms, Intel AlderLake-S uses Synopsys SerDes where
all the SerDes PLL configurations are controlled by the xPCS at the BIOS
level. If the driver perform a xPCS soft reset on initialization, these
settings will be switched back to the power on reset values.

This patch introduced a new xpcs_reset() function for drivers such as
sja1105 and stmmac to decide whether or not to perform a xPCS soft
reset.

Suggested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Cc: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Michael Sit Wei Hong <michael.wei.hong.sit@intel.com>
Signed-off-by: Wong Vee Khee <vee.khee.wong@linux.intel.com>
---
 drivers/net/dsa/sja1105/sja1105_mdio.c        |  6 ++-
 .../net/ethernet/stmicro/stmmac/stmmac_mdio.c | 15 +++++++-
 drivers/net/pcs/pcs-xpcs.c                    | 37 ++++++++++---------
 include/linux/pcs/pcs-xpcs.h                  |  4 +-
 include/linux/stmmac.h                        |  1 +
 5 files changed, 40 insertions(+), 23 deletions(-)

Comments

Andrew Lunn Aug. 27, 2021, 2:03 a.m. UTC | #1 
On Fri, Aug 27, 2021 at 07:51:32AM +0800, Wong Vee Khee wrote:
> Unlike any other platforms, Intel AlderLake-S uses Synopsys SerDes where
> all the SerDes PLL configurations are controlled by the xPCS at the BIOS
> level. If the driver perform a xPCS soft reset on initialization, these
> settings will be switched back to the power on reset values.

So you have given up on the idea of calling into the BIOS to do this?
ACPI is too difficult to use? Can you at least copy the code from the
BIOS into the driver? It might then also be possible to fix your
inability to swap link speeds?

	  Andrew
diff mbox series

Patch

diff --git a/drivers/net/dsa/sja1105/sja1105_mdio.c b/drivers/net/dsa/sja1105/sja1105_mdio.c
index 705d3900e43a..6f8cc1358ac0 100644
--- a/drivers/net/dsa/sja1105/sja1105_mdio.c
+++ b/drivers/net/dsa/sja1105/sja1105_mdio.c
@@ -435,13 +435,17 @@  static int sja1105_mdiobus_pcs_register(struct sja1105_private *priv)
 			goto out_pcs_free;
 		}
 
-		xpcs = xpcs_create(mdiodev, priv->phy_mode[port]);
+		xpcs = xpcs_create(mdiodev);
 		if (IS_ERR(xpcs)) {
 			rc = PTR_ERR(xpcs);
 			goto out_pcs_free;
 		}
 
 		priv->xpcs[port] = xpcs;
+
+		rc = xpcs_reset(xpcs, priv->phy_mode[port]);
+		if (rc)
+			goto out_pcs_free;
 	}
 
 	priv->mdio_pcs = bus;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
index a5d150c5f3d8..50f0e6dccb85 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
@@ -401,12 +401,15 @@  int stmmac_xpcs_setup(struct mii_bus *bus)
 {
 	struct net_device *ndev = bus->priv;
 	struct mdio_device *mdiodev;
+	bool skip_xpcs_soft_reset;
 	struct stmmac_priv *priv;
 	struct dw_xpcs *xpcs;
 	int mode, addr;
+	int err;
 
 	priv = netdev_priv(ndev);
 	mode = priv->plat->phy_interface;
+	skip_xpcs_soft_reset = priv->plat->skip_xpcs_soft_reset;
 
 	/* Try to probe the XPCS by scanning all addresses. */
 	for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
@@ -414,12 +417,20 @@  int stmmac_xpcs_setup(struct mii_bus *bus)
 		if (IS_ERR(mdiodev))
 			continue;
 
-		xpcs = xpcs_create(mdiodev, mode);
-		if (IS_ERR_OR_NULL(xpcs)) {
+		xpcs = xpcs_create(mdiodev);
+		if (IS_ERR(xpcs)) {
 			mdio_device_free(mdiodev);
 			continue;
 		}
 
+		if (!skip_xpcs_soft_reset) {
+			err = xpcs_reset(xpcs, mode);
+			if (err) {
+				mdio_device_free(mdiodev);
+				continue;
+			}
+		}
+
 		priv->hw->xpcs = xpcs;
 		break;
 	}
diff --git a/drivers/net/pcs/pcs-xpcs.c b/drivers/net/pcs/pcs-xpcs.c
index fb0a83dc09ac..e4961884dd96 100644
--- a/drivers/net/pcs/pcs-xpcs.c
+++ b/drivers/net/pcs/pcs-xpcs.c
@@ -252,6 +252,18 @@  static int xpcs_soft_reset(struct dw_xpcs *xpcs,
 	return xpcs_poll_reset(xpcs, dev);
 }
 
+int xpcs_reset(struct dw_xpcs *xpcs, phy_interface_t interface)
+{
+	const struct xpcs_compat *compat;
+
+	compat = xpcs_find_compat(xpcs->id, interface);
+	if (!compat)
+		return -ENODEV;
+
+	return xpcs_soft_reset(xpcs, compat);
+}
+EXPORT_SYMBOL_GPL(xpcs_reset);
+
 #define xpcs_warn(__xpcs, __state, __args...) \
 ({ \
 	if ((__state)->link) \
@@ -1084,12 +1096,11 @@  static const struct phylink_pcs_ops xpcs_phylink_ops = {
 	.pcs_link_up = xpcs_link_up,
 };
 
-struct dw_xpcs *xpcs_create(struct mdio_device *mdiodev,
-			    phy_interface_t interface)
+struct dw_xpcs *xpcs_create(struct mdio_device *mdiodev)
 {
 	struct dw_xpcs *xpcs;
 	u32 xpcs_id;
-	int i, ret;
+	int i;
 
 	xpcs = kzalloc(sizeof(*xpcs), GFP_KERNEL);
 	if (!xpcs)
@@ -1099,37 +1110,27 @@  struct dw_xpcs *xpcs_create(struct mdio_device *mdiodev,
 
 	xpcs_id = xpcs_get_id(xpcs);
 
+	/* If Device ID are all ones, there is no device found */
+	if (xpcs_id == 0xffffffff)
+		goto out;
+
 	for (i = 0; i < ARRAY_SIZE(xpcs_id_list); i++) {
 		const struct xpcs_id *entry = &xpcs_id_list[i];
-		const struct xpcs_compat *compat;
 
 		if ((xpcs_id & entry->mask) != entry->id)
 			continue;
 
 		xpcs->id = entry;
-
-		compat = xpcs_find_compat(entry, interface);
-		if (!compat) {
-			ret = -ENODEV;
-			goto out;
-		}
-
 		xpcs->pcs.ops = &xpcs_phylink_ops;
 		xpcs->pcs.poll = true;
 
-		ret = xpcs_soft_reset(xpcs, compat);
-		if (ret)
-			goto out;
-
 		return xpcs;
 	}
 
-	ret = -ENODEV;
-
 out:
 	kfree(xpcs);
 
-	return ERR_PTR(ret);
+	return ERR_PTR(-ENODEV);
 }
 EXPORT_SYMBOL_GPL(xpcs_create);
 
diff --git a/include/linux/pcs/pcs-xpcs.h b/include/linux/pcs/pcs-xpcs.h
index add077a81b21..d841f55f12cc 100644
--- a/include/linux/pcs/pcs-xpcs.h
+++ b/include/linux/pcs/pcs-xpcs.h
@@ -35,8 +35,8 @@  void xpcs_validate(struct dw_xpcs *xpcs, unsigned long *supported,
 		   struct phylink_link_state *state);
 int xpcs_config_eee(struct dw_xpcs *xpcs, int mult_fact_100ns,
 		    int enable);
-struct dw_xpcs *xpcs_create(struct mdio_device *mdiodev,
-			    phy_interface_t interface);
+int xpcs_reset(struct dw_xpcs *xpcs, phy_interface_t interface);
+struct dw_xpcs *xpcs_create(struct mdio_device *mdiodev);
 void xpcs_destroy(struct dw_xpcs *xpcs);
 
 #endif /* __LINUX_PCS_XPCS_H */
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index a6f03b36fc4f..0f901773c5e4 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -268,5 +268,6 @@  struct plat_stmmacenet_data {
 	int msi_rx_base_vec;
 	int msi_tx_base_vec;
 	bool use_phy_wol;
+	bool skip_xpcs_soft_reset;
 };
 #endif