tg3: 5719: Prevent tx data corruption

This patch enables a bit that prevents read DMA overflows and adjusts
the txmbuf margin from the hardware default.  The combination of these
modifications prevents a tx data corruption issue we were seeing on the
5719.
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

@@ -7857,7 +7857,10 @@ static int tg3_reset_hw(struct tg3 *tp, int reset_phy)
 	tw32(BUFMGR_DMA_HIGH_WATER,
 	     tp->bufmgr_config.dma_high_water);
 
-	tw32(BUFMGR_MODE, BUFMGR_MODE_ENABLE | BUFMGR_MODE_ATTN_ENABLE);
+	val = BUFMGR_MODE_ENABLE | BUFMGR_MODE_ATTN_ENABLE;
+	if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5719)
+		val |= BUFMGR_MODE_NO_TX_UNDERRUN;
+	tw32(BUFMGR_MODE, val);
 	for (i = 0; i < 2000; i++) {
 		if (tr32(BUFMGR_MODE) & BUFMGR_MODE_ENABLE)
 			break;
@@ -8037,6 +8040,13 @@ static int tg3_reset_hw(struct tg3 *tp, int reset_phy)
 		     val | TG3_RDMA_RSRVCTRL_FIFO_OFLW_FIX);
 	}
 
+	if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5719) {
+		val = tr32(TG3_LSO_RD_DMA_CRPTEN_CTRL);
+		tw32(TG3_LSO_RD_DMA_CRPTEN_CTRL, val |
+		     TG3_LSO_RD_DMA_CRPTEN_CTRL_BLEN_BD_4K |
+		     TG3_LSO_RD_DMA_CRPTEN_CTRL_BLEN_LSO_4K);
+	}
+
 	/* Receive/send statistics. */
 	if (tp->tg3_flags2 & TG3_FLG2_5750_PLUS) {
 		val = tr32(RCVLPC_STATS_ENABLE);

drivers/net/tg3.h

@@ -1225,6 +1225,7 @@
 #define  BUFMGR_MODE_ATTN_ENABLE	 0x00000004
 #define  BUFMGR_MODE_BM_TEST		 0x00000008
 #define  BUFMGR_MODE_MBLOW_ATTN_ENAB	 0x00000010
+#define  BUFMGR_MODE_NO_TX_UNDERRUN	 0x80000000
 #define BUFMGR_STATUS			0x00004404
 #define  BUFMGR_STATUS_ERROR		 0x00000004
 #define  BUFMGR_STATUS_MBLOW		 0x00000010
@@ -1306,7 +1307,12 @@
 
 #define TG3_RDMA_RSRVCTRL_REG		0x00004900
 #define TG3_RDMA_RSRVCTRL_FIFO_OFLW_FIX	 0x00000004
-/* 0x4904 --> 0x4c00 unused */
+/* 0x4904 --> 0x4910 unused */
+
+#define TG3_LSO_RD_DMA_CRPTEN_CTRL	0x00004910
+#define TG3_LSO_RD_DMA_CRPTEN_CTRL_BLEN_BD_4K	 0x00030000
+#define TG3_LSO_RD_DMA_CRPTEN_CTRL_BLEN_LSO_4K	 0x000c0000
+/* 0x4914 --> 0x4c00 unused */
 
 /* Write DMA control registers */
 #define WDMAC_MODE			0x00004c00