wifi: rtl8xxxu: Fix reading the vendor of combo chips

[ Upstream commit 6f103ae ]

The wifi + bluetooth combo chips (RTL8723AU and RTL8723BU) read the
chip vendor from the wrong register because the val32 variable gets
overwritten. Add one more variable to avoid this.

This had no real effect on RTL8723BU. It may have had an effect on
RTL8723AU.

Fixes: 26f1fad ("New driver: rtl8xxxu (mac80211)")
Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/24af8024-2f07-552b-93d8-38823d8e3cb0@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c

@@ -1608,18 +1608,18 @@ static int rtl8xxxu_identify_chip(struct rtl8xxxu_priv *priv)
 {
 	struct device *dev = &priv->udev->dev;
 	struct ieee80211_hw *hw = priv->hw;
-	u32 val32, bonding;
+	u32 val32, bonding, sys_cfg;
 	u16 val16;
 
-	val32 = rtl8xxxu_read32(priv, REG_SYS_CFG);
-	priv->chip_cut = (val32 & SYS_CFG_CHIP_VERSION_MASK) >>
+	sys_cfg = rtl8xxxu_read32(priv, REG_SYS_CFG);
+	priv->chip_cut = (sys_cfg & SYS_CFG_CHIP_VERSION_MASK) >>
 		SYS_CFG_CHIP_VERSION_SHIFT;
-	if (val32 & SYS_CFG_TRP_VAUX_EN) {
+	if (sys_cfg & SYS_CFG_TRP_VAUX_EN) {
 		dev_info(dev, "Unsupported test chip\n");
 		return -ENOTSUPP;
 	}
 
-	if (val32 & SYS_CFG_BT_FUNC) {
+	if (sys_cfg & SYS_CFG_BT_FUNC) {
 		if (priv->chip_cut >= 3) {
 			sprintf(priv->chip_name, "8723BU");
 			priv->rtl_chip = RTL8723B;
@@ -1641,7 +1641,7 @@ static int rtl8xxxu_identify_chip(struct rtl8xxxu_priv *priv)
 		if (val32 & MULTI_GPS_FUNC_EN)
 			priv->has_gps = 1;
 		priv->is_multi_func = 1;
-	} else if (val32 & SYS_CFG_TYPE_ID) {
+	} else if (sys_cfg & SYS_CFG_TYPE_ID) {
 		bonding = rtl8xxxu_read32(priv, REG_HPON_FSM);
 		bonding &= HPON_FSM_BONDING_MASK;
 		if (priv->fops->tx_desc_size ==
@@ -1692,7 +1692,7 @@ static int rtl8xxxu_identify_chip(struct rtl8xxxu_priv *priv)
 	case RTL8188E:
 	case RTL8192E:
 	case RTL8723B:
-		switch (val32 & SYS_CFG_VENDOR_EXT_MASK) {
+		switch (sys_cfg & SYS_CFG_VENDOR_EXT_MASK) {
 		case SYS_CFG_VENDOR_ID_TSMC:
 			sprintf(priv->chip_vendor, "TSMC");
 			break;
@@ -1709,7 +1709,7 @@ static int rtl8xxxu_identify_chip(struct rtl8xxxu_priv *priv)
 		}
 		break;
 	default:
-		if (val32 & SYS_CFG_VENDOR_ID) {
+		if (sys_cfg & SYS_CFG_VENDOR_ID) {
 			sprintf(priv->chip_vendor, "UMC");
 			priv->vendor_umc = 1;
 		} else {