r8169: identify different registers.

Documentation (sort of).

The location are the same, the values are the same but it is
just accidental. Note that the 810x could cope with a smaller
value as it does not support jumbo frames.
Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Cc: Hayes <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/r8169.c

@@ -67,7 +67,6 @@ static const int multicast_filter_limit = 32;
 #define RX_FIFO_THRESH	7	/* 7 means NO threshold, Rx buffer level before first PCI xfer. */
 #define RX_DMA_BURST	6	/* Maximum PCI burst, '6' is 1024 */
 #define TX_DMA_BURST	6	/* Maximum PCI burst, '6' is 1024 */
-#define EarlyTxThld	0x3F	/* 0x3F means NO early transmit */
 #define SafeMtu		0x1c20	/* ... actually life sucks beyond ~7k */
 #define InterFrameGap	0x03	/* 3 means InterFrameGap = the shortest one */
 
@@ -231,7 +230,14 @@ enum rtl_registers {
 	IntrMitigate	= 0xe2,
 	RxDescAddrLow	= 0xe4,
 	RxDescAddrHigh	= 0xe8,
-	EarlyTxThres	= 0xec,
+	EarlyTxThres	= 0xec,	/* 8169. Unit of 32 bytes. */
+
+#define NoEarlyTx	0x3f	/* Max value : no early transmit. */
+
+	MaxTxPacketSize	= 0xec,	/* 8101/8168. Unit of 128 bytes. */
+
+#define TxPacketMax	(8064 >> 7)
+
 	FuncEvent	= 0xf0,
 	FuncEventMask	= 0xf4,
 	FuncPresetState	= 0xf8,
@@ -2901,7 +2907,7 @@ static void rtl_hw_start_8169(struct net_device *dev)
 	    (tp->mac_version == RTL_GIGA_MAC_VER_04))
 		RTL_W8(ChipCmd, CmdTxEnb | CmdRxEnb);
 
-	RTL_W8(EarlyTxThres, EarlyTxThld);
+	RTL_W8(EarlyTxThres, NoEarlyTx);
 
 	rtl_set_rx_max_size(ioaddr, rx_buf_sz);
 
@@ -3036,7 +3042,7 @@ static void rtl_hw_start_8168bef(void __iomem *ioaddr, struct pci_dev *pdev)
 {
 	rtl_hw_start_8168bb(ioaddr, pdev);
 
-	RTL_W8(EarlyTxThres, EarlyTxThld);
+	RTL_W8(MaxTxPacketSize, TxPacketMax);
 
 	RTL_W8(Config4, RTL_R8(Config4) & ~(1 << 0));
 }
@@ -3091,7 +3097,7 @@ static void rtl_hw_start_8168cp_3(void __iomem *ioaddr, struct pci_dev *pdev)
 	/* Magic. */
 	RTL_W8(DBG_REG, 0x20);
 
-	RTL_W8(EarlyTxThres, EarlyTxThld);
+	RTL_W8(MaxTxPacketSize, TxPacketMax);
 
 	rtl_tx_performance_tweak(pdev, 0x5 << MAX_READ_REQUEST_SHIFT);
 
@@ -3147,7 +3153,7 @@ static void rtl_hw_start_8168d(void __iomem *ioaddr, struct pci_dev *pdev)
 
 	rtl_disable_clock_request(pdev);
 
-	RTL_W8(EarlyTxThres, EarlyTxThld);
+	RTL_W8(MaxTxPacketSize, TxPacketMax);
 
 	rtl_tx_performance_tweak(pdev, 0x5 << MAX_READ_REQUEST_SHIFT);
 
@@ -3162,7 +3168,7 @@ static void rtl_hw_start_8168(struct net_device *dev)
 
 	RTL_W8(Cfg9346, Cfg9346_Unlock);
 
-	RTL_W8(EarlyTxThres, EarlyTxThld);
+	RTL_W8(MaxTxPacketSize, TxPacketMax);
 
 	rtl_set_rx_max_size(ioaddr, rx_buf_sz);
 
@@ -3342,7 +3348,7 @@ static void rtl_hw_start_8101(struct net_device *dev)
 
 	RTL_W8(Cfg9346, Cfg9346_Unlock);
 
-	RTL_W8(EarlyTxThres, EarlyTxThld);
+	RTL_W8(MaxTxPacketSize, TxPacketMax);
 
 	rtl_set_rx_max_size(ioaddr, rx_buf_sz);