[PATCH 4.19 06/32] net: ethernet: stmmac: fix altr_tse_pcs function when using a fixed-link

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Dinh Nguyen <dinguyen@kernel.org>

[ Upstream commit a6aaa00324240967272b451bfa772547bd576ee6 ]

When using a fixed-link, the altr_tse_pcs driver crashes
due to null-pointer dereference as no phy_device is provided to
tse_pcs_fix_mac_speed function. Fix this by adding a check for
phy_dev before calling the tse_pcs_fix_mac_speed() function.

Also clean up the tse_pcs_fix_mac_speed function a bit. There is
no need to check for splitter_base and sgmii_adapter_base
because the driver will fail if these 2 variables are not
derived from the device tree.

Fixes: fb3bbdb85989 ("net: ethernet: Add TSE PCS support to dwmac-socfpga")
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/stmicro/stmmac/altr_tse_pcs.c  |  8 --------
 drivers/net/ethernet/stmicro/stmmac/altr_tse_pcs.h  |  4 ++++
 drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c | 13 +++++--------
 3 files changed, 9 insertions(+), 16 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/altr_tse_pcs.c b/drivers/net/ethernet/stmicro/stmmac/altr_tse_pcs.c
index 8b50afcdb52d..729df169faa2 100644
--- a/drivers/net/ethernet/stmicro/stmmac/altr_tse_pcs.c
+++ b/drivers/net/ethernet/stmicro/stmmac/altr_tse_pcs.c
@@ -68,10 +68,6 @@
 #define TSE_PCS_USE_SGMII_ENA				BIT(0)
 #define TSE_PCS_IF_USE_SGMII				0x03
 
-#define SGMII_ADAPTER_CTRL_REG				0x00
-#define SGMII_ADAPTER_DISABLE				0x0001
-#define SGMII_ADAPTER_ENABLE				0x0000
-
 #define AUTONEGO_LINK_TIMER				20
 
 static int tse_pcs_reset(void __iomem *base, struct tse_pcs *pcs)
@@ -213,12 +209,8 @@ void tse_pcs_fix_mac_speed(struct tse_pcs *pcs, struct phy_device *phy_dev,
 			   unsigned int speed)
 {
 	void __iomem *tse_pcs_base = pcs->tse_pcs_base;
-	void __iomem *sgmii_adapter_base = pcs->sgmii_adapter_base;
 	u32 val;
 
-	writew(SGMII_ADAPTER_ENABLE,
-	       sgmii_adapter_base + SGMII_ADAPTER_CTRL_REG);
-
 	pcs->autoneg = phy_dev->autoneg;
 
 	if (phy_dev->autoneg == AUTONEG_ENABLE) {
diff --git a/drivers/net/ethernet/stmicro/stmmac/altr_tse_pcs.h b/drivers/net/ethernet/stmicro/stmmac/altr_tse_pcs.h
index 2f5882450b06..254199f2efdb 100644
--- a/drivers/net/ethernet/stmicro/stmmac/altr_tse_pcs.h
+++ b/drivers/net/ethernet/stmicro/stmmac/altr_tse_pcs.h
@@ -21,6 +21,10 @@
 #include <linux/phy.h>
 #include <linux/timer.h>
 
+#define SGMII_ADAPTER_CTRL_REG		0x00
+#define SGMII_ADAPTER_ENABLE		0x0000
+#define SGMII_ADAPTER_DISABLE		0x0001
+
 struct tse_pcs {
 	struct device *dev;
 	void __iomem *tse_pcs_base;
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
index 33407df6bea6..32ead4a4b460 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
@@ -29,9 +29,6 @@
 
 #include "altr_tse_pcs.h"
 
-#define SGMII_ADAPTER_CTRL_REG                          0x00
-#define SGMII_ADAPTER_DISABLE                           0x0001
-
 #define SYSMGR_EMACGRP_CTRL_PHYSEL_ENUM_GMII_MII 0x0
 #define SYSMGR_EMACGRP_CTRL_PHYSEL_ENUM_RGMII 0x1
 #define SYSMGR_EMACGRP_CTRL_PHYSEL_ENUM_RMII 0x2
@@ -65,16 +62,14 @@ static void socfpga_dwmac_fix_mac_speed(void *priv, unsigned int speed)
 {
 	struct socfpga_dwmac *dwmac = (struct socfpga_dwmac *)priv;
 	void __iomem *splitter_base = dwmac->splitter_base;
-	void __iomem *tse_pcs_base = dwmac->pcs.tse_pcs_base;
 	void __iomem *sgmii_adapter_base = dwmac->pcs.sgmii_adapter_base;
 	struct device *dev = dwmac->dev;
 	struct net_device *ndev = dev_get_drvdata(dev);
 	struct phy_device *phy_dev = ndev->phydev;
 	u32 val;
 
-	if ((tse_pcs_base) && (sgmii_adapter_base))
-		writew(SGMII_ADAPTER_DISABLE,
-		       sgmii_adapter_base + SGMII_ADAPTER_CTRL_REG);
+	writew(SGMII_ADAPTER_DISABLE,
+	       sgmii_adapter_base + SGMII_ADAPTER_CTRL_REG);
 
 	if (splitter_base) {
 		val = readl(splitter_base + EMAC_SPLITTER_CTRL_REG);
@@ -96,7 +91,9 @@ static void socfpga_dwmac_fix_mac_speed(void *priv, unsigned int speed)
 		writel(val, splitter_base + EMAC_SPLITTER_CTRL_REG);
 	}
 
-	if (tse_pcs_base && sgmii_adapter_base)
+	writew(SGMII_ADAPTER_ENABLE,
+	       sgmii_adapter_base + SGMII_ADAPTER_CTRL_REG);
+	if (phy_dev)
 		tse_pcs_fix_mac_speed(&dwmac->pcs, phy_dev, speed);
 }
 
-- 
2.35.1