net: dsa: microchip: Utilize error values in ksz8_w_sta_mac_table()

To handle potential read/write operation failures, update
ksz8_w_sta_mac_table() to make use of the return values provided by
read/write functions.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/dsa/microchip/ksz8795.c

@@ -358,19 +358,26 @@ static int ksz8_r_table(struct ksz_device *dev, int table, u16 addr, u64 *data)
 	return ret;
 }
 
-static void ksz8_w_table(struct ksz_device *dev, int table, u16 addr, u64 data)
+static int ksz8_w_table(struct ksz_device *dev, int table, u16 addr, u64 data)
 {
 	const u16 *regs;
 	u16 ctrl_addr;
+	int ret;
 
 	regs = dev->info->regs;
 
 	ctrl_addr = IND_ACC_TABLE(table) | addr;
 
 	mutex_lock(&dev->alu_mutex);
-	ksz_write64(dev, regs[REG_IND_DATA_HI], data);
-	ksz_write16(dev, regs[REG_IND_CTRL_0], ctrl_addr);
+	ret = ksz_write64(dev, regs[REG_IND_DATA_HI], data);
+	if (ret)
+		goto unlock_alu;
+
+	ret = ksz_write16(dev, regs[REG_IND_CTRL_0], ctrl_addr);
+unlock_alu:
 	mutex_unlock(&dev->alu_mutex);
+
+	return ret;
 }
 
 static int ksz8_valid_dyn_entry(struct ksz_device *dev, u8 *data)
@@ -510,8 +517,8 @@ static int ksz8_r_sta_mac_table(struct ksz_device *dev, u16 addr,
 	return 0;
 }
 
-static void ksz8_w_sta_mac_table(struct ksz_device *dev, u16 addr,
-				 struct alu_struct *alu)
+static int ksz8_w_sta_mac_table(struct ksz_device *dev, u16 addr,
+				struct alu_struct *alu)
 {
 	u32 data_hi, data_lo;
 	const u8 *shifts;
@@ -539,7 +546,8 @@ static void ksz8_w_sta_mac_table(struct ksz_device *dev, u16 addr,
 		data_hi &= ~masks[STATIC_MAC_TABLE_OVERRIDE];
 
 	data = (u64)data_hi << 32 | data_lo;
-	ksz8_w_table(dev, TABLE_STATIC_MAC, addr, data);
+
+	return ksz8_w_table(dev, TABLE_STATIC_MAC, addr, data);
 }
 
 static void ksz8_from_vlan(struct ksz_device *dev, u32 vlan, u8 *fid,
@@ -1035,9 +1043,8 @@ static int ksz8_add_sta_mac(struct ksz_device *dev, int port,
 		/* Need a way to map VID to FID. */
 		alu.fid = vid;
 	}
-	ksz8_w_sta_mac_table(dev, index, &alu);
 
-	return 0;
+	return ksz8_w_sta_mac_table(dev, index, &alu);
 }
 
 static int ksz8_del_sta_mac(struct ksz_device *dev, int port,
@@ -1061,16 +1068,14 @@ static int ksz8_del_sta_mac(struct ksz_device *dev, int port,
 
 	/* no available entry */
 	if (index == dev->info->num_statics)
-		goto exit;
+		return 0;
 
 	/* clear port */
 	alu.port_forward &= ~BIT(port);
 	if (!alu.port_forward)
 		alu.is_static = false;
-	ksz8_w_sta_mac_table(dev, index, &alu);
 
-exit:
-	return 0;
+	return ksz8_w_sta_mac_table(dev, index, &alu);
 }
 
 int ksz8_mdb_add(struct ksz_device *dev, int port,
@@ -1394,9 +1399,7 @@ int ksz8_enable_stp_addr(struct ksz_device *dev)
 	alu.is_override = true;
 	alu.port_forward = dev->info->cpu_ports;
 
-	ksz8_w_sta_mac_table(dev, 0, &alu);
-
-	return 0;
+	return ksz8_w_sta_mac_table(dev, 0, &alu);
 }
 
 int ksz8_setup(struct dsa_switch *ds)