s390/qeth: enable only required csum offload features

Current code attempts to enable all advertised HW csum offload features.
Future-proof this by enabling only those features that we actually use.

Also, the IPv4 header csum feature is only needed for TX on L3 devices.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 5f450df..3172004 100644 (file)
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -6329,8 +6329,11 @@ static int qeth_send_checksum_on(struct qeth_card *card, int cstype,
        struct qeth_checksum_cmd chksum_cb;
        int rc;
 
-       if (prot == QETH_PROT_IPV4)
+       /* some L3 HW requires combined L3+L4 csum offload: */
+       if (IS_LAYER3(card) && prot == QETH_PROT_IPV4 &&
+           cstype == IPA_OUTBOUND_CHECKSUM)
                required_features |= QETH_IPA_CHECKSUM_IP_HDR;
+
        rc = qeth_ipa_checksum_run_cmd(card, cstype, IPA_CMD_ASS_START, 0,
                                       &chksum_cb, prot);
        if (!rc) {
@@ -6351,8 +6354,12 @@ static int qeth_send_checksum_on(struct qeth_card *card, int cstype,
                         prot, QETH_CARD_IFNAME(card));
                return rc;
        }
+
+       if (chksum_cb.supported & QETH_IPA_CHECKSUM_LP2LP)
+               required_features |= QETH_IPA_CHECKSUM_LP2LP;
+
        rc = qeth_ipa_checksum_run_cmd(card, cstype, IPA_CMD_ASS_ENABLE,
-                                      chksum_cb.supported, &chksum_cb,
+                                      required_features, &chksum_cb,
                                       prot);
        if (!rc) {
                if ((required_features & chksum_cb.enabled) !=