qeth: Fix IP version detection for VLAN traffic

The current code would always return 0 for VLAN-encapsulated IP traffic.
One notable side effect was that VLAN traffic would never get prioritized
on OSD and OSX devices when priority queueing modes prio_queueing_tos or
prio_queueing_prec were enabled.

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

1 files changed, 5 insertions, 2 deletions

diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h
index a0de045eb227..5333b2c018e7 100644
--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -854,8 +854,11 @@ static inline int qeth_get_micros(void)
 
 static inline int qeth_get_ip_version(struct sk_buff *skb)
 {
-        struct ethhdr *ehdr = (struct ethhdr *)skb->data;
-        switch (ehdr->h_proto) {
+        __be16 *p = &((struct ethhdr *)skb->data)->h_proto;
+
+        if (*p == ETH_P_8021Q)
+                p += 2;
+        switch (*p) {
         case ETH_P_IPV6:
                 return 6;
         case ETH_P_IP: