qeth: core code should alloc headroom for LLC protocol

Allocate headroom for TR_HLEN but using only ETH_HLEN causes rx
performance degradation. Allocate ETH_HLEN for ethernet and
TR_HLEN for token ring (layer 3 mode).

Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 5cfe0ef7719a..055f5c3e7b56 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -4002,7 +4002,11 @@ struct sk_buff *qeth_core_get_next_skb(struct qeth_card *card,
                 }
         } else {
                 skb_len = (*hdr)->hdr.l3.length;
-                headroom = max((int)ETH_HLEN, (int)TR_HLEN);
+                if ((card->info.link_type == QETH_LINK_TYPE_LANE_TR) ||
+                    (card->info.link_type == QETH_LINK_TYPE_HSTR))
+                        headroom = TR_HLEN;
+                else
+                        headroom = ETH_HLEN;
         }
 
         if (!skb_len)