staging: rtl8192u: fix read_nic_* functions

read_nic_*() functions are defined in r8192U_core.c.
They call internally usb_control_msg() to read the
nic registers and return the value read.
Following a remark made by Dan Carpenter, if usb_control_msg()
fails, the value returned will be invalid.

To accommodate for this, this patch changes the functions
to take a pointer as argument to set the value read and
return 0 on success and the error status on failure, so
that callers of read_nic_*() can check the return status.

Some other fixes introduced in read_nic_*() functions are:

The expressions (1<<EPROM_*_SHIFT) used to address and set
the individual bits of the eeprom register were replaced
with EPROM_*_BIT bitmasks to make the code more intuitive.
EPROM_*_BIT bitmasks were defined in r8192U_hw.h and
EPROM_*_SHIFT were removed.

In netdev_err(), which is called in case of failure,
the hardcoded function name in the error log message was
replaced with __func__ to reduce line size.
Also, from the error log message, it was omitted the word
"Timeout" and it is just reported the error code since the
failure can not only be due to timeout expiration but also
due to a memory allocation failure. In case of timeout
expiration, usb_start_wait_urb() prints an appropriate log
message when debug is enabled.

Finally, some minor fixes to the coding style were applied in
lines affected by the above changes, including the removal
of ifdef DEBUG_RX (the debugging of reads and writes of the
nic registers shall be done with explicit check on their
return status which will be added in a follow on patch).

Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 25 insertions, 21 deletions

diff --git a/drivers/staging/rtl8192u/r8192U_dm.c b/drivers/staging/rtl8192u/r8192U_dm.c
index c591476..a6e4c37 100644
--- a/drivers/staging/rtl8192u/r8192U_dm.c
+++ b/drivers/staging/rtl8192u/r8192U_dm.c
@@ -480,7 +480,7 @@ static void dm_check_rate_adaptive(struct net_device *dev)
 		//
 		// Check whether updating of RATR0 is required
 		//
-		currentRATR = read_nic_dword(dev, RATR0);
+		read_nic_dword(dev, RATR0, &currentRATR);
 		if(targetRATR !=  currentRATR)
 		{
 			u32 ratr_value;
@@ -634,7 +634,7 @@ static void dm_TXPowerTrackingCallback_TSSI(struct net_device *dev)
 	//DbgPrint("hi, vivi, strange\n");
 	for(i = 0;i <= 30; i++)
 	{
-		Pwr_Flag = read_nic_byte(dev, 0x1ba);
+		read_nic_byte(dev, 0x1ba, &Pwr_Flag);
 
 		if (Pwr_Flag == 0)
 		{
@@ -642,9 +642,9 @@ static void dm_TXPowerTrackingCallback_TSSI(struct net_device *dev)
 			continue;
 		}
 #ifdef RTL8190P
-		Avg_TSSI_Meas = read_nic_word(dev, 0x1bc);
+		read_nic_word(dev, 0x1bc, &Avg_TSSI_Meas);
 #else
-		Avg_TSSI_Meas = read_nic_word(dev, 0x13c);
+		read_nic_word(dev, 0x13c, &Avg_TSSI_Meas);
 #endif
 		if(Avg_TSSI_Meas == 0)
 		{
@@ -655,12 +655,12 @@ static void dm_TXPowerTrackingCallback_TSSI(struct net_device *dev)
 		for(k = 0;k < 5; k++)
 		{
 #ifdef RTL8190P
-			tmp_report[k] = read_nic_byte(dev, 0x1d8+k);
+			read_nic_byte(dev, 0x1d8+k, &tmp_report[k]);
 #else
 			if(k !=4)
-				tmp_report[k] = read_nic_byte(dev, 0x134+k);
+				read_nic_byte(dev, 0x134+k, &tmp_report[k]);
 			else
-				tmp_report[k] = read_nic_byte(dev, 0x13e);
+				read_nic_byte(dev, 0x13e, &tmp_report[k]);
 #endif
 			RT_TRACE(COMP_POWER_TRACKING, "TSSI_report_value = %d\n", tmp_report[k]);
 		}
@@ -2397,6 +2397,7 @@ static void dm_initial_gain(
 	u8					initial_gain=0;
 	static u8				initialized, force_write;
 	static u32			reset_cnt;
+	u8				tmp;
 
 	if(dm_digtable.dig_algorithm_switch)
 	{
@@ -2437,7 +2438,8 @@ static void dm_initial_gain(
 		reset_cnt = priv->reset_count;
 	}
 
-	if(dm_digtable.pre_ig_value != read_nic_byte(dev, rOFDM0_XAAGCCore1))
+	read_nic_byte(dev, rOFDM0_XAAGCCore1, &tmp);
+	if (dm_digtable.pre_ig_value != tmp)
 		force_write = 1;
 
 	{
@@ -2727,7 +2729,8 @@ static void dm_check_edca_turbo(
 			// TODO:  Modified this part and try to set acm control in only 1 IO processing!!
 
 					PACI_AIFSN	pAciAifsn = (PACI_AIFSN)&(qos_parameters->aifs[0]);
-					u8		AcmCtrl = read_nic_byte(dev, AcmHwCtrl);
+					u8		AcmCtrl;
+					read_nic_byte(dev, AcmHwCtrl, &AcmCtrl);
 					if(pAciAifsn->f.ACM)
 					{ // ACM bit is 1.
 						AcmCtrl |= AcmHw_BeqEn;
@@ -2881,7 +2884,7 @@ static	void	dm_check_pbc_gpio(struct net_device *dev)
 	u8 tmp1byte;
 
 
-	tmp1byte = read_nic_byte(dev,GPI);
+	read_nic_byte(dev, GPI, &tmp1byte);
 	if(tmp1byte == 0xff)
 		return;
 
@@ -2933,7 +2936,7 @@ extern	void	dm_gpio_change_rf_callback(struct work_struct *work)
 		{
 			// 0x108 GPIO input register is read only
 			//set 0x108 B1= 1: RF-ON; 0: RF-OFF.
-			tmp1byte = read_nic_byte(dev,GPI);
+			read_nic_byte(dev, GPI, &tmp1byte);
 
 			eRfPowerStateToSet = (tmp1byte&BIT1) ?  eRfOn : eRfOff;
 
@@ -2996,7 +2999,7 @@ extern	void	dm_rf_pathcheck_workitemcallback(struct work_struct *work)
 
 	/* 2008/01/30 MH After discussing with SD3 Jerry, 0xc04/0xd04 register will
 	   always be the same. We only read 0xc04 now. */
-	rfpath = read_nic_byte(dev, 0xc04);
+	read_nic_byte(dev, 0xc04, &rfpath);
 
 	// Check Bit 0-3, it means if RF A-D is enabled.
 	for (i = 0; i < RF90_PATH_MAX; i++)
@@ -3052,12 +3055,13 @@ static void dm_rxpath_sel_byrssi(struct net_device *dev)
 
 	if(!cck_Rx_Path_initialized)
 	{
-		DM_RxPathSelTable.cck_Rx_path = (read_nic_byte(dev, 0xa07)&0xf);
+		read_nic_byte(dev, 0xa07, &DM_RxPathSelTable.cck_Rx_path);
+		DM_RxPathSelTable.cck_Rx_path &= 0xf;
 		cck_Rx_Path_initialized = 1;
 	}
 
-	DM_RxPathSelTable.disabledRF = 0xf;
-	DM_RxPathSelTable.disabledRF &= ~(read_nic_byte(dev, 0xc04));
+	read_nic_byte(dev, 0xc04, &DM_RxPathSelTable.disabledRF);
+	DM_RxPathSelTable.disabledRF = ~DM_RxPathSelTable.disabledRF & 0xf;
 
 	if(priv->ieee80211->mode == WIRELESS_MODE_B)
 	{
@@ -3731,17 +3735,17 @@ extern void dm_shadow_init(struct net_device *dev)
 	for (page = 0; page < 5; page++)
 		for (offset = 0; offset < 256; offset++)
 		{
-			dm_shadow[page][offset] = read_nic_byte(dev, offset+page*256);
+			read_nic_byte(dev, offset+page*256, &dm_shadow[page][offset]);
 			//DbgPrint("P-%d/O-%02x=%02x\r\n", page, offset, DM_Shadow[page][offset]);
 		}
 
 	for (page = 8; page < 11; page++)
 		for (offset = 0; offset < 256; offset++)
-			dm_shadow[page][offset] = read_nic_byte(dev, offset+page*256);
+			read_nic_byte(dev, offset+page*256, &dm_shadow[page][offset]);
 
 	for (page = 12; page < 15; page++)
 		for (offset = 0; offset < 256; offset++)
-			dm_shadow[page][offset] = read_nic_byte(dev, offset+page*256);
+			read_nic_byte(dev, offset+page*256, &dm_shadow[page][offset]);
 
 }   /* dm_shadow_init */
 
@@ -3858,14 +3862,14 @@ static void dm_check_txrateandretrycount(struct net_device *dev)
 	struct ieee80211_device *ieee = priv->ieee80211;
 	//for 11n tx rate
 //	priv->stats.CurrentShowTxate = read_nic_byte(dev, Current_Tx_Rate_Reg);
-	ieee->softmac_stats.CurrentShowTxate = read_nic_byte(dev, Current_Tx_Rate_Reg);
+	read_nic_byte(dev, Current_Tx_Rate_Reg, &ieee->softmac_stats.CurrentShowTxate);
 	//printk("=============>tx_rate_reg:%x\n", ieee->softmac_stats.CurrentShowTxate);
 	//for initial tx rate
 //	priv->stats.last_packet_rate = read_nic_byte(dev, Initial_Tx_Rate_Reg);
-	ieee->softmac_stats.last_packet_rate = read_nic_byte(dev ,Initial_Tx_Rate_Reg);
+	read_nic_byte(dev, Initial_Tx_Rate_Reg, &ieee->softmac_stats.last_packet_rate);
 	//for tx tx retry count
 //	priv->stats.txretrycount = read_nic_dword(dev, Tx_Retry_Count_Reg);
-	ieee->softmac_stats.txretrycount = read_nic_dword(dev, Tx_Retry_Count_Reg);
+	read_nic_dword(dev, Tx_Retry_Count_Reg, &ieee->softmac_stats.txretrycount);
 }
 
 static void dm_send_rssi_tofw(struct net_device *dev)