IB/ipath: Fix maximum MTU reporting

Although our chip supports 4K MTUs, our driver doesn't yet support
this feature, so limit the maximum MTU to 2K until we get support for
4K MTUs implemented.

Signed-off-by: Robert Walsh <robert.walsh@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/ipath/ipath_mad.c

@@ -292,7 +292,12 @@ static int recv_subn_get_portinfo(struct ib_smp *smp,
 	/* pip->vl_arb_high_cap; // only one VL */
 	/* pip->vl_arb_low_cap; // only one VL */
 	/* InitTypeReply = 0 */
-	pip->inittypereply_mtucap = IB_MTU_4096;
+	/*
+	 * Note: the chips support a maximum MTU of 4096, but the driver
+	 * hasn't implemented this feature yet, so set the maximum value
+	 * to 2048.
+	 */
+	pip->inittypereply_mtucap = IB_MTU_2048;
 	// HCAs ignore VLStallCount and HOQLife
 	/* pip->vlstallcnt_hoqlife; */
 	pip->operationalvl_pei_peo_fpi_fpo = 0x10;	/* OVLs = 1 */