mv643xx_eth: use longer DMA bursts

The mv643xx_eth driver is limiting DMA bursts to 32 bytes, while
using the largest burst size (128 bytes) gives a couple percentage
points performance improvement in throughput tests, and the docs
say that the 128 byte default should not need to be changed, so
use 128 byte bursts instead.
Signed-off-by: NLennert Buytenhek <buytenh@marvell.com>

drivers/net/mv643xx_eth.c

@@ -129,21 +129,21 @@ static char mv643xx_eth_driver_version[] = "1.1";
 /*
  * SDMA configuration register.
  */
-#define RX_BURST_SIZE_4_64BIT		(2 << 1)
+#define RX_BURST_SIZE_16_64BIT		(4 << 1)
 #define BLM_RX_NO_SWAP			(1 << 4)
 #define BLM_TX_NO_SWAP			(1 << 5)
-#define TX_BURST_SIZE_4_64BIT		(2 << 22)
+#define TX_BURST_SIZE_16_64BIT		(4 << 22)
 
 #if defined(__BIG_ENDIAN)
 #define PORT_SDMA_CONFIG_DEFAULT_VALUE		\
-		RX_BURST_SIZE_4_64BIT	|	\
-		TX_BURST_SIZE_4_64BIT
+		RX_BURST_SIZE_16_64BIT	|	\
+		TX_BURST_SIZE_16_64BIT
 #elif defined(__LITTLE_ENDIAN)
 #define PORT_SDMA_CONFIG_DEFAULT_VALUE		\
-		RX_BURST_SIZE_4_64BIT	|	\
+		RX_BURST_SIZE_16_64BIT	|	\
 		BLM_RX_NO_SWAP		|	\
 		BLM_TX_NO_SWAP		|	\
-		TX_BURST_SIZE_4_64BIT
+		TX_BURST_SIZE_16_64BIT
 #else
 #error One of __BIG_ENDIAN or __LITTLE_ENDIAN must be defined
 #endif