[PATCH net-next] net: hns: Fix for variable may be used uninitialized warnings

[Huazhong Tan]

When !CONFIG_REGMAP hns throws compiler warnings since
dsaf_read_syscon ignores the return result from regmap_read,
which allows val to be uninitialized.

Fixes: 86897c960b49 ("net: hns: add syscon operation for dsaf")
Reported-by: Jason Gunthorpe <j...@ziepe.ca>
Signed-off-by: Huazhong Tan <tanhuazh...@huawei.com>
Signed-off-by: Yunsheng Lin <linyunsh...@huawei.com>
---
 drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c | 52 +++++++++++++++-------
 drivers/net/ethernet/hisilicon/hns/hns_dsaf_reg.h  |  7 +--
 2 files changed, 38 insertions(+), 21 deletions(-)

diff --git a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c 
b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c
index ca247c2..acf2963 100644
--- a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c
+++ b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c
@@ -44,12 +44,17 @@ static void dsaf_write_sub(struct dsaf_device *dsaf_dev, 
u32 reg, u32 val)
 
 static u32 dsaf_read_sub(struct dsaf_device *dsaf_dev, u32 reg)
 {
-       u32 ret;
-
-       if (dsaf_dev->sub_ctrl)
-               ret = dsaf_read_syscon(dsaf_dev->sub_ctrl, reg);
-       else
+       u32 ret = 0;
+       int err;
+
+       if (dsaf_dev->sub_ctrl) {
+               err = dsaf_read_syscon(dsaf_dev->sub_ctrl, reg, &ret);
+               if (err)
+                       dev_err(dsaf_dev->dev, "dsaf_read_syscon error %d!\n",
+                               err);
+       } else {
                ret = dsaf_read_reg(dsaf_dev->sc_base, reg);
+       }
 
        return ret;
 }
@@ -188,18 +193,23 @@ static void cpld_led_reset_acpi(struct hns_mac_cb *mac_cb)
 static int cpld_set_led_id(struct hns_mac_cb *mac_cb,
                           enum hnae_led_state status)
 {
+       u32 val = 0;
+       int ret;
+
        if (!mac_cb->cpld_ctrl)
                return 0;
 
        switch (status) {
        case HNAE_LED_ACTIVE:
-               mac_cb->cpld_led_value =
-                       dsaf_read_syscon(mac_cb->cpld_ctrl,
-                                        mac_cb->cpld_ctrl_reg);
-               dsaf_set_bit(mac_cb->cpld_led_value, DSAF_LED_ANCHOR_B,
-                            CPLD_LED_ON_VALUE);
+               ret = dsaf_read_syscon(mac_cb->cpld_ctrl, mac_cb->cpld_ctrl_reg,
+                                      &val);
+               if (ret)
+                       return ret;
+
+               dsaf_set_bit(val, DSAF_LED_ANCHOR_B, CPLD_LED_ON_VALUE);
                dsaf_write_syscon(mac_cb->cpld_ctrl, mac_cb->cpld_ctrl_reg,
-                                 mac_cb->cpld_led_value);
+                                 val);
+               mac_cb->cpld_led_value = val;
                break;
        case HNAE_LED_INACTIVE:
                dsaf_set_bit(mac_cb->cpld_led_value, DSAF_LED_ANCHOR_B,
@@ -560,12 +570,19 @@ static phy_interface_t hns_mac_get_phy_if_acpi(struct 
hns_mac_cb *mac_cb)
 
 int hns_mac_get_sfp_prsnt(struct hns_mac_cb *mac_cb, int *sfp_prsnt)
 {
+       u32 val = 0;
+       int ret;
+
        if (!mac_cb->cpld_ctrl)
                return -ENODEV;
 
-       *sfp_prsnt = !dsaf_read_syscon(mac_cb->cpld_ctrl, mac_cb->cpld_ctrl_reg
-                                       + MAC_SFP_PORT_OFFSET);
+       ret = dsaf_read_syscon(mac_cb->cpld_ctrl,
+                              mac_cb->cpld_ctrl_reg + MAC_SFP_PORT_OFFSET,
+                              &val);
+       if (ret)
+               return ret;
 
+       *sfp_prsnt = !val;
        return 0;
 }
 
@@ -615,7 +632,7 @@ static int hns_mac_config_sds_loopback(struct hns_mac_cb 
*mac_cb, bool en)
 #define RX_CSR(lane, reg) ((0x4080 + (reg) * 0x0002 + (lane) * 0x0200) * 2)
        u64 reg_offset = RX_CSR(lane_id[mac_cb->mac_id], 0);
 
-       int sfp_prsnt;
+       int sfp_prsnt = 0;
        int ret = hns_mac_get_sfp_prsnt(mac_cb, &sfp_prsnt);
 
        if (!mac_cb->phy_dev) {
@@ -627,7 +644,7 @@ static int hns_mac_config_sds_loopback(struct hns_mac_cb 
*mac_cb, bool en)
        }
 
        if (mac_cb->serdes_ctrl) {
-               u32 origin;
+               u32 origin = 0;
 
                if (!AE_IS_VER1(mac_cb->dsaf_dev->dsaf_ver)) {
 #define HILINK_ACCESS_SEL_CFG          0x40008
@@ -644,7 +661,10 @@ static int hns_mac_config_sds_loopback(struct hns_mac_cb 
*mac_cb, bool en)
                                                  HILINK_ACCESS_SEL_CFG, 3);
                }
 
-               origin = dsaf_read_syscon(mac_cb->serdes_ctrl, reg_offset);
+               ret = dsaf_read_syscon(mac_cb->serdes_ctrl, reg_offset,
+                                      &origin);
+               if (ret)
+                       return ret;
 
                dsaf_set_field(origin, 1ull << 10, 10, en);
                dsaf_write_syscon(mac_cb->serdes_ctrl, reg_offset, origin);
diff --git a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_reg.h 
b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_reg.h
index 46a52d9..886cbbf 100644
--- a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_reg.h
+++ b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_reg.h
@@ -1034,12 +1034,9 @@ static inline void dsaf_write_syscon(struct regmap 
*base, u32 reg, u32 value)
        regmap_write(base, reg, value);
 }
 
-static inline u32 dsaf_read_syscon(struct regmap *base, u32 reg)
+static inline int dsaf_read_syscon(struct regmap *base, u32 reg, u32 *val)
 {
-       unsigned int val;
-
-       regmap_read(base, reg, &val);
-       return val;
+       return regmap_read(base, reg, val);
 }
 
 #define dsaf_read_dev(a, reg) \
-- 
1.9.1