tg3: Improve 5785 PCIe performance

This patch improves 5785 performance by allowing the write DMA engine to
request larger DMA burst sizes than it otherwise would.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Reviewed-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/tg3.c

@@ -7633,6 +7633,9 @@ static int tg3_reset_hw(struct tg3 *tp, int reset_phy)
 	if (tp->tg3_flags3 & TG3_FLG3_5755_PLUS)
 		val |= WDMAC_MODE_STATUS_TAG_FIX;
 
+	if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5785)
+		val |= WDMAC_MODE_BURST_ALL_DATA;
+
 	tw32_f(WDMAC_MODE, val);
 	udelay(40);
 

drivers/net/tg3.h

@@ -1266,6 +1266,7 @@
 #define  WDMAC_MODE_LNGREAD_ENAB	 0x00000200
 #define  WDMAC_MODE_RX_ACCEL		 0x00000400
 #define  WDMAC_MODE_STATUS_TAG_FIX	 0x20000000
+#define  WDMAC_MODE_BURST_ALL_DATA	 0xc0000000
 #define WDMAC_STATUS			0x00004c04
 #define  WDMAC_STATUS_TGTABORT		 0x00000004
 #define  WDMAC_STATUS_MSTABORT		 0x00000008