rtlwifi: set proper udelay within rf_serial_read

Since read RF register is an indirect access that hardware needs time to
accomplish read action, but there's no ready bit, so delay is required to
guarantee the read value is correct. After investigating internal documents,
these delays are reduced as proper values.
Reported-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/realtek/rtlwifi/rtl8188ee/phy.c

@@ -164,9 +164,9 @@ static u32 _rtl88e_phy_rf_serial_read(struct ieee80211_hw *hw,
 	    (newoffset << 23) | BLSSIREADEDGE;
 	rtl_set_bbreg(hw, RFPGA0_XA_HSSIPARAMETER2, MASKDWORD,
 		      tmplong & (~BLSSIREADEDGE));
-	mdelay(1);
+	udelay(10);
 	rtl_set_bbreg(hw, pphyreg->rfhssi_para2, MASKDWORD, tmplong2);
-	mdelay(2);
+	udelay(120);
 	if (rfpath == RF90_PATH_A)
 		rfpi_enable = (u8)rtl_get_bbreg(hw, RFPGA0_XA_HSSIPARAMETER1,
 						BIT(8));

drivers/net/wireless/realtek/rtlwifi/rtl8192ee/phy.c

@@ -158,9 +158,8 @@ static u32 _rtl92ee_phy_rf_serial_read(struct ieee80211_hw *hw,
 		   (newoffset << 23) | BLSSIREADEDGE;
 	rtl_set_bbreg(hw, RFPGA0_XA_HSSIPARAMETER2, MASKDWORD,
 		      tmplong & (~BLSSIREADEDGE));
-	mdelay(1);
 	rtl_set_bbreg(hw, pphyreg->rfhssi_para2, MASKDWORD, tmplong2);
-	mdelay(2);
+	udelay(20);
 	if (rfpath == RF90_PATH_A)
 		rfpi_enable = (u8)rtl_get_bbreg(hw, RFPGA0_XA_HSSIPARAMETER1,
 						BIT(8));

drivers/net/wireless/realtek/rtlwifi/rtl8723com/phy_common.c

@@ -89,12 +89,10 @@ u32 rtl8723_phy_rf_serial_read(struct ieee80211_hw *hw,
 	    (newoffset << 23) | BLSSIREADEDGE;
 	rtl_set_bbreg(hw, RFPGA0_XA_HSSIPARAMETER2, MASKDWORD,
 		      tmplong & (~BLSSIREADEDGE));
-	mdelay(1);
 	rtl_set_bbreg(hw, pphyreg->rfhssi_para2, MASKDWORD, tmplong2);
-	mdelay(1);
 	rtl_set_bbreg(hw, RFPGA0_XA_HSSIPARAMETER2, MASKDWORD,
 		      tmplong | BLSSIREADEDGE);
-	mdelay(1);
+	udelay(120);
 	if (rfpath == RF90_PATH_A)
 		rfpi_enable = (u8) rtl_get_bbreg(hw, RFPGA0_XA_HSSIPARAMETER1,
 						 BIT(8));