tg3: Assign correct tx margin for 5719

Commit d309a46e, entitled
"tg3: 5719: Prevent tx data corruption", was supposed to contain the tx
margin adjustment but it looks like it somehow was omitted.  This patch
fixes the problem.
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

@@ -8206,6 +8206,10 @@ static int tg3_reset_hw(struct tg3 *tp, int reset_phy)
 	    GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_57780 ||
 	    (tp->tg3_flags3 & TG3_FLG3_5717_PLUS)) {
 		val = tr32(TG3_RDMA_RSRVCTRL_REG);
+		if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5719) {
+			val &= ~TG3_RDMA_RSRVCTRL_TXMRGN_MASK;
+			val |= TG3_RDMA_RSRVCTRL_TXMRGN_320B;
+		}
 		tw32(TG3_RDMA_RSRVCTRL_REG,
 		     val | TG3_RDMA_RSRVCTRL_FIFO_OFLW_FIX);
 	}

drivers/net/tg3.h

@@ -1327,6 +1327,8 @@
 
 #define TG3_RDMA_RSRVCTRL_REG		0x00004900
 #define TG3_RDMA_RSRVCTRL_FIFO_OFLW_FIX	 0x00000004
+#define TG3_RDMA_RSRVCTRL_TXMRGN_320B	 0x28000000
+#define TG3_RDMA_RSRVCTRL_TXMRGN_MASK	 0xffe00000
 /* 0x4904 --> 0x4910 unused */
 
 #define TG3_LSO_RD_DMA_CRPTEN_CTRL	0x00004910