net: axienet: reduce default RX interrupt threshold to 1

Now that NAPI has been implemented, the hardware interrupt mitigation
mechanism is not needed to avoid excessive interrupt load in most cases.
Reduce the default RX interrupt threshold to 1 to reduce introduced
latency. This can be increased with ethtool if desired if some applications
still want to reduce interrupts.

Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/xilinx/xilinx_axienet.h

@@ -122,7 +122,7 @@
 /* Default TX/RX Threshold and waitbound values for SGDMA mode */
 #define XAXIDMA_DFT_TX_THRESHOLD	24
 #define XAXIDMA_DFT_TX_WAITBOUND	254
-#define XAXIDMA_DFT_RX_THRESHOLD	24
+#define XAXIDMA_DFT_RX_THRESHOLD	1
 #define XAXIDMA_DFT_RX_WAITBOUND	254
 
 #define XAXIDMA_BD_CTRL_TXSOF_MASK	0x08000000 /* First tx packet */