net: dsa: qca8k: check return value of read functions correctly

Current return type of qca8k_mii_read32() and qca8k_read() are
unsigned, it can't be negative, so the return value check is
unuseful. For check the return value correctly, change return
type of the read functions and add a output parameter to store
the read value.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c
index 1f1b7c4..d761c59 100644 (file)
--- a/drivers/net/dsa/qca8k.c
+++ b/drivers/net/dsa/qca8k.c
@@ -89,26 +89,26 @@ qca8k_split_addr(u32 regaddr, u16 *r1, u16 *r2, u16 *page)
        *page = regaddr & 0x3ff;
 }
 
-static u32
-qca8k_mii_read32(struct mii_bus *bus, int phy_id, u32 regnum)
+static int
+qca8k_mii_read32(struct mii_bus *bus, int phy_id, u32 regnum, u32 *val)
 {
-       u32 val;
        int ret;
 
        ret = bus->read(bus, phy_id, regnum);
        if (ret >= 0) {
-               val = ret;
+               *val = ret;
                ret = bus->read(bus, phy_id, regnum + 1);
-               val |= ret << 16;
+               *val |= ret << 16;
        }
 
        if (ret < 0) {
                dev_err_ratelimited(&bus->dev,
                                    "failed to read qca8k 32bit register\n");
+               *val = 0;
                return ret;
        }
 
-       return val;
+       return 0;
 }
 
 static void
@@ -148,26 +148,26 @@ qca8k_set_page(struct mii_bus *bus, u16 page)
        return 0;
 }
 
-static u32
-qca8k_read(struct qca8k_priv *priv, u32 reg)
+static int
+qca8k_read(struct qca8k_priv *priv, u32 reg, u32 *val)
 {
        struct mii_bus *bus = priv->bus;
        u16 r1, r2, page;
-       u32 val;
+       int ret;
 
        qca8k_split_addr(reg, &r1, &r2, &page);
 
        mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
 
-       val = qca8k_set_page(bus, page);
-       if (val < 0)
+       ret = qca8k_set_page(bus, page);
+       if (ret < 0)
                goto exit;
 
-       val = qca8k_mii_read32(bus, 0x10 | r2, r1);
+       ret = qca8k_mii_read32(bus, 0x10 | r2, r1, val);
 
 exit:
        mutex_unlock(&bus->mdio_lock);
-       return val;
+       return ret;
 }
 
 static int
@@ -208,11 +208,9 @@ qca8k_rmw(struct qca8k_priv *priv, u32 reg, u32 mask, u32 write_val)
        if (ret < 0)
                goto exit;
 
-       val = qca8k_mii_read32(bus, 0x10 | r2, r1);
-       if (val < 0) {
-               ret = val;
+       ret = qca8k_mii_read32(bus, 0x10 | r2, r1, &val);
+       if (ret < 0)
                goto exit;
-       }
 
        val &= ~mask;
        val |= write_val;
@@ -240,15 +238,8 @@ static int
 qca8k_regmap_read(void *ctx, uint32_t reg, uint32_t *val)
 {
        struct qca8k_priv *priv = (struct qca8k_priv *)ctx;
-       int ret;
-
-       ret = qca8k_read(priv, reg);
-       if (ret < 0)
-               return ret;
-
-       *val = ret;
 
-       return 0;
+       return qca8k_read(priv, reg, val);
 }
 
 static int
@@ -296,18 +287,18 @@ static struct regmap_config qca8k_regmap_config = {
 static int
 qca8k_busy_wait(struct qca8k_priv *priv, u32 reg, u32 mask)
 {
+       int ret, ret1;
        u32 val;
-       int ret;
 
-       ret = read_poll_timeout(qca8k_read, val, !(val & mask),
+       ret = read_poll_timeout(qca8k_read, ret1, !(val & mask),
                                0, QCA8K_BUSY_WAIT_TIMEOUT * USEC_PER_MSEC, false,
-                               priv, reg);
+                               priv, reg, &val);
 
        /* Check if qca8k_read has failed for a different reason
         * before returning -ETIMEDOUT
         */
-       if (ret < 0 && val < 0)
-               return val;
+       if (ret < 0 && ret1 < 0)
+               return ret1;
 
        return ret;
 }
@@ -316,13 +307,13 @@ static int
 qca8k_fdb_read(struct qca8k_priv *priv, struct qca8k_fdb *fdb)
 {
        u32 reg[4], val;
-       int i;
+       int i, ret;
 
        /* load the ARL table into an array */
        for (i = 0; i < 4; i++) {
-               val = qca8k_read(priv, QCA8K_REG_ATU_DATA0 + (i * 4));
-               if (val < 0)
-                       return val;
+               ret = qca8k_read(priv, QCA8K_REG_ATU_DATA0 + (i * 4), &val);
+               if (ret < 0)
+                       return ret;
 
                reg[i] = val;
        }
@@ -396,9 +387,9 @@ qca8k_fdb_access(struct qca8k_priv *priv, enum qca8k_fdb_cmd cmd, int port)
 
        /* Check for table full violation when adding an entry */
        if (cmd == QCA8K_FDB_LOAD) {
-               reg = qca8k_read(priv, QCA8K_REG_ATU_FUNC);
-               if (reg < 0)
-                       return reg;
+               ret = qca8k_read(priv, QCA8K_REG_ATU_FUNC, &reg);
+               if (ret < 0)
+                       return ret;
                if (reg & QCA8K_ATU_FUNC_FULL)
                        return -1;
        }
@@ -477,9 +468,9 @@ qca8k_vlan_access(struct qca8k_priv *priv, enum qca8k_vlan_cmd cmd, u16 vid)
 
        /* Check for table full violation when adding an entry */
        if (cmd == QCA8K_VLAN_LOAD) {
-               reg = qca8k_read(priv, QCA8K_REG_VTU_FUNC1);
-               if (reg < 0)
-                       return reg;
+               ret = qca8k_read(priv, QCA8K_REG_VTU_FUNC1, &reg);
+               if (ret < 0)
+                       return ret;
                if (reg & QCA8K_VTU_FUNC1_FULL)
                        return -ENOMEM;
        }
@@ -505,11 +496,9 @@ qca8k_vlan_add(struct qca8k_priv *priv, u8 port, u16 vid, bool untagged)
        if (ret < 0)
                goto out;
 
-       reg = qca8k_read(priv, QCA8K_REG_VTU_FUNC0);
-       if (reg < 0) {
-               ret = reg;
+       ret = qca8k_read(priv, QCA8K_REG_VTU_FUNC0, &reg);
+       if (ret < 0)
                goto out;
-       }
        reg |= QCA8K_VTU_FUNC0_VALID | QCA8K_VTU_FUNC0_IVL_EN;
        reg &= ~(QCA8K_VTU_FUNC0_EG_MODE_MASK << QCA8K_VTU_FUNC0_EG_MODE_S(port));
        if (untagged)
@@ -542,11 +531,9 @@ qca8k_vlan_del(struct qca8k_priv *priv, u8 port, u16 vid)
        if (ret < 0)
                goto out;
 
-       reg = qca8k_read(priv, QCA8K_REG_VTU_FUNC0);
-       if (reg < 0) {
-               ret = reg;
+       ret = qca8k_read(priv, QCA8K_REG_VTU_FUNC0, &reg);
+       if (ret < 0)
                goto out;
-       }
        reg &= ~(3 << QCA8K_VTU_FUNC0_EG_MODE_S(port));
        reg |= QCA8K_VTU_FUNC0_EG_MODE_NOT <<
                        QCA8K_VTU_FUNC0_EG_MODE_S(port);
@@ -638,19 +625,19 @@ qca8k_mdio_busy_wait(struct mii_bus *bus, u32 reg, u32 mask)
 {
        u16 r1, r2, page;
        u32 val;
-       int ret;
+       int ret, ret1;
 
        qca8k_split_addr(reg, &r1, &r2, &page);
 
-       ret = read_poll_timeout(qca8k_mii_read32, val, !(val & mask), 0,
+       ret = read_poll_timeout(qca8k_mii_read32, ret1, !(val & mask), 0,
                                QCA8K_BUSY_WAIT_TIMEOUT * USEC_PER_MSEC, false,
-                               bus, 0x10 | r2, r1);
+                               bus, 0x10 | r2, r1, &val);
 
        /* Check if qca8k_read has failed for a different reason
         * before returnting -ETIMEDOUT
         */
-       if (ret < 0 && val < 0)
-               return val;
+       if (ret < 0 && ret1 < 0)
+               return ret1;
 
        return ret;
 }
@@ -725,7 +712,7 @@ qca8k_mdio_read(struct mii_bus *salve_bus, int phy, int regnum)
        if (ret)
                goto exit;
 
-       val = qca8k_mii_read32(bus, 0x10 | r2, r1);
+       ret = qca8k_mii_read32(bus, 0x10 | r2, r1, &val);
 
 exit:
        /* even if the busy_wait timeouts try to clear the MASTER_EN */
@@ -733,10 +720,10 @@ exit:
 
        mutex_unlock(&bus->mdio_lock);
 
-       if (val >= 0)
-               val &= QCA8K_MDIO_MASTER_DATA_MASK;
+       if (ret >= 0)
+               ret = val & QCA8K_MDIO_MASTER_DATA_MASK;
 
-       return val;
+       return ret;
 }
 
 static int
@@ -1211,7 +1198,7 @@ qca8k_phylink_mac_config(struct dsa_switch *ds, int port, unsigned int mode,
                qca8k_write(priv, reg, QCA8K_PORT_PAD_SGMII_EN);
 
                /* Enable/disable SerDes auto-negotiation as necessary */
-               val = qca8k_read(priv, QCA8K_REG_PWS);
+               qca8k_read(priv, QCA8K_REG_PWS, &val);
                if (phylink_autoneg_inband(mode))
                        val &= ~QCA8K_PWS_SERDES_AEN_DIS;
                else
@@ -1219,7 +1206,7 @@ qca8k_phylink_mac_config(struct dsa_switch *ds, int port, unsigned int mode,
                qca8k_write(priv, QCA8K_REG_PWS, val);
 
                /* Configure the SGMII parameters */
-               val = qca8k_read(priv, QCA8K_REG_SGMII_CTRL);
+               qca8k_read(priv, QCA8K_REG_SGMII_CTRL, &val);
 
                val |= QCA8K_SGMII_EN_PLL | QCA8K_SGMII_EN_RX |
                        QCA8K_SGMII_EN_TX | QCA8K_SGMII_EN_SD;
@@ -1314,10 +1301,11 @@ qca8k_phylink_mac_link_state(struct dsa_switch *ds, int port,
 {
        struct qca8k_priv *priv = ds->priv;
        u32 reg;
+       int ret;
 
-       reg = qca8k_read(priv, QCA8K_REG_PORT_STATUS(port));
-       if (reg < 0)
-               return reg;
+       ret = qca8k_read(priv, QCA8K_REG_PORT_STATUS(port), &reg);
+       if (ret < 0)
+               return ret;
 
        state->link = !!(reg & QCA8K_PORT_STATUS_LINK_UP);
        state->an_complete = state->link;
@@ -1419,19 +1407,20 @@ qca8k_get_ethtool_stats(struct dsa_switch *ds, int port,
        struct qca8k_priv *priv = (struct qca8k_priv *)ds->priv;
        const struct qca8k_mib_desc *mib;
        u32 reg, i, val;
-       u64 hi;
+       u64 hi = 0;
+       int ret;
 
        for (i = 0; i < ARRAY_SIZE(ar8327_mib); i++) {
                mib = &ar8327_mib[i];
                reg = QCA8K_PORT_MIB_COUNTER(port) + mib->offset;
 
-               val = qca8k_read(priv, reg);
-               if (val < 0)
+               ret = qca8k_read(priv, reg, &val);
+               if (ret < 0)
                        continue;
 
                if (mib->size == 2) {
-                       hi = qca8k_read(priv, reg + 4);
-                       if (hi < 0)
+                       ret = qca8k_read(priv, reg + 4, (u32 *)&hi);
+                       if (ret < 0)
                                continue;
                }
 
@@ -1459,7 +1448,7 @@ qca8k_set_mac_eee(struct dsa_switch *ds, int port, struct ethtool_eee *eee)
        int ret;
 
        mutex_lock(&priv->reg_mutex);
-       reg = qca8k_read(priv, QCA8K_REG_EEE_CTRL);
+       ret = qca8k_read(priv, QCA8K_REG_EEE_CTRL, &reg);
        if (reg < 0) {
                ret = reg;
                goto exit;
@@ -1793,14 +1782,15 @@ static int qca8k_read_switch_id(struct qca8k_priv *priv)
        const struct qca8k_match_data *data;
        u32 val;
        u8 id;
+       int ret;
 
        /* get the switches ID from the compatible */
        data = of_device_get_match_data(priv->dev);
        if (!data)
                return -ENODEV;
 
-       val = qca8k_read(priv, QCA8K_REG_MASK_CTRL);
-       if (val < 0)
+       ret = qca8k_read(priv, QCA8K_REG_MASK_CTRL, &val);
+       if (ret < 0)
                return -ENODEV;
 
        id = QCA8K_MASK_CTRL_DEVICE_ID(val & QCA8K_MASK_CTRL_DEVICE_ID_MASK);