tg3: Disable new DMA engine for 57766

A bug was found in the new DMA engine for the 57766.  This patch
disables it, which causes the device to fallback to the old DMA engine.

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/ethernet/broadcom/tg3.c

@@ -8896,9 +8896,6 @@ static int tg3_reset_hw(struct tg3 *tp, int reset_phy)
 	if (tg3_flag(tp, PCI_EXPRESS))
 		rdmac_mode |= RDMAC_MODE_FIFO_LONG_BURST;
 
-	if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_57766)
-		rdmac_mode |= RDMAC_MODE_JMB_2K_MMRR;
-
 	if (tg3_flag(tp, HW_TSO_1) ||
 	    tg3_flag(tp, HW_TSO_2) ||
 	    tg3_flag(tp, HW_TSO_3))
@@ -14190,8 +14187,6 @@ static int __devinit tg3_get_invariants(struct tg3 *tp)
 
 	if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5719)
 		tp->dma_limit = TG3_TX_BD_DMA_MAX_4K;
-	else if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_57766)
-		tp->dma_limit = TG3_TX_BD_DMA_MAX_2K;
 
 	if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5717 ||
 	    GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5719 ||