tg3: Apply short DMA frag workaround to 5906

commit b7abee6e upstream.

5906 devices also need the short DMA fragment workaround.  This patch
makes the necessary change.
Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Mike Pagano <mpagano@gentoo.org>

drivers/net/tg3.c

@@ -13689,7 +13689,8 @@ static int __devinit tg3_get_invariants(struct tg3 *tp)
 	 */
 	tg3_flag_set(tp, 4G_DMA_BNDRY_BUG);
 
-	if (tg3_flag(tp, 5755_PLUS))
+	if (tg3_flag(tp, 5755_PLUS) ||
+		GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5906)
 			tg3_flag_set(tp, SHORT_DMA_BUG);
 	else
 		tg3_flag_set(tp, 40BIT_DMA_LIMIT_BUG);