qeth: Increase default MTU for OSA devices

Increase the default MTU for real OSA devices in layer 2 mode
to 1500 Bytes for increased compatibility.

Signed-off-by: Stefan Raspl <raspl@linux.vnet.ibm.com>
Signed-off-by: Frank Blaschka <blaschka@linux.vnet.ibm.com>
Reviewed-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 6cd0fc1b203a..f161a10a6579 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -2198,11 +2198,11 @@ static inline int qeth_get_initial_mtu_for_card(struct qeth_card *card)
                 case QETH_LINK_TYPE_LANE_TR:
                         return 2000;
                 default:
-                        return 1492;
+                        return card->options.layer2 ? 1500 : 1492;
                 }
         case QETH_CARD_TYPE_OSM:
         case QETH_CARD_TYPE_OSX:
-                return 1492;
+                return card->options.layer2 ? 1500 : 1492;
         default:
                 return 1500;
         }
@@ -2275,9 +2275,10 @@ static int qeth_ulp_enable_cb(struct qeth_card *card, struct qeth_reply *reply,
                 card->info.max_mtu = mtu;
                 card->qdio.in_buf_size = mtu + 2 * PAGE_SIZE;
         } else {
-                card->info.initial_mtu = qeth_get_initial_mtu_for_card(card);
                 card->info.max_mtu = *(__u16 *)QETH_ULP_ENABLE_RESP_MAX_MTU(
                         iob->data);
+                card->info.initial_mtu = min(card->info.max_mtu,
+                                        qeth_get_initial_mtu_for_card(card));
                 card->qdio.in_buf_size = QETH_IN_BUF_SIZE_DEFAULT;
         }