tg3: Fix int generation hw bug for 5719 / 5720

On the 5719 and 5720, there is a bug where the hardware will
misinterpret a status tag update and leave interrupts permanently
disabled.  This patch enables a hardware fix that works around the
issue.

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

drivers/net/tg3.c

@@ -8198,6 +8198,9 @@ static int tg3_reset_hw(struct tg3 *tp, int reset_phy)
 		      ~DMA_RWCTRL_DIS_CACHE_ALIGNMENT;
 		if (tp->pci_chip_rev_id == CHIPREV_ID_57765_A0)
 			val &= ~DMA_RWCTRL_CRDRDR_RDMA_MRRS_MSK;
+		if (GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_57765 &&
+		    GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5717)
+			val |= DMA_RWCTRL_TAGGED_STAT_WA;
 		tw32(TG3PCI_DMA_RW_CTRL, val | tp->dma_rwctrl);
 	} else if (GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5784 &&
 		   GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5761) {

drivers/net/tg3.h

@@ -188,6 +188,7 @@
 #define   METAL_REV_B2			 0x02
 #define TG3PCI_DMA_RW_CTRL		0x0000006c
 #define  DMA_RWCTRL_DIS_CACHE_ALIGNMENT  0x00000001
+#define  DMA_RWCTRL_TAGGED_STAT_WA	 0x00000080
 #define  DMA_RWCTRL_CRDRDR_RDMA_MRRS_MSK 0x00000380
 #define  DMA_RWCTRL_READ_BNDRY_MASK	 0x00000700
 #define  DMA_RWCTRL_READ_BNDRY_DISAB	 0x00000000