tg3: Add read dma workaround for 5720

Commit 091f0ea30074bc43f9250961b3247af713024bc6 "tg3: Add New 5719 Read
DMA workaround" added a workaround for TX DMA stall on the 5719. This
workaround needs to be applied to the 5720 as well.

Cc: stable@vger.kernel.org
Reported-by: Roland Dreier <roland@purestorage.com>
Tested-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nithin Nayak Sujir <nsujir@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/broadcom/tg3.h b/drivers/net/ethernet/broadcom/tg3.h
index 9b2d3ac..ff6e30e 100644
--- a/drivers/net/ethernet/broadcom/tg3.h
+++ b/drivers/net/ethernet/broadcom/tg3.h
@@ -1422,7 +1422,8 @@
 #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
-#define TG3_LSO_RD_DMA_TX_LENGTH_WA	 0x02000000
+#define TG3_LSO_RD_DMA_TX_LENGTH_WA_5719	 0x02000000
+#define TG3_LSO_RD_DMA_TX_LENGTH_WA_5720	 0x00200000
 /* 0x4914 --> 0x4be0 unused */
 
 #define TG3_NUM_RDMA_CHANNELS		4
@@ -3059,7 +3060,7 @@
 	TG3_FLAG_APE_HAS_NCSI,
 	TG3_FLAG_TX_TSTAMP_EN,
 	TG3_FLAG_4K_FIFO_LIMIT,
-	TG3_FLAG_5719_RDMA_BUG,
+	TG3_FLAG_5719_5720_RDMA_BUG,
 	TG3_FLAG_RESET_TASK_PENDING,
 	TG3_FLAG_PTP_CAPABLE,
 	TG3_FLAG_5705_PLUS,