kernel: add missing description for GRO optimization patch

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

SVN-Revision: 44798

target/linux/generic/patches-3.18/680-net-skip-gro-for-otherhost-packets.patch

@@ -1,3 +1,17 @@
+Subject: NET: skip GRO for otherhost packets
+
+For network drivers using napi_gro_receive, packets are run through GRO,
+even when the destination MAC address does not match, and they're supposed
+to be delivered to another host behind a different bridge port.
+
+This can be very expensive, because for drivers without TSO or scatter-
+gather, this can only be undone by copying the skb and checksumming it
+again.
+
+Fix this by leaving skbs with PACKET_OTHERHOST untouched.
+
+Signed-off-by: Felix Fietkau <nbd@openwrt.org>
+
 --- a/net/core/dev.c
 +++ b/net/core/dev.c
 @@ -4003,6 +4003,9 @@ static enum gro_result dev_gro_receive(s

target/linux/generic/patches-3.19/680-net-skip-gro-for-otherhost-packets.patch

@@ -1,3 +1,17 @@
+Subject: NET: skip GRO for otherhost packets
+
+For network drivers using napi_gro_receive, packets are run through GRO,
+even when the destination MAC address does not match, and they're supposed
+to be delivered to another host behind a different bridge port.
+
+This can be very expensive, because for drivers without TSO or scatter-
+gather, this can only be undone by copying the skb and checksumming it
+again.
+
+Fix this by leaving skbs with PACKET_OTHERHOST untouched.
+
+Signed-off-by: Felix Fietkau <nbd@openwrt.org>
+
 --- a/net/core/dev.c
 +++ b/net/core/dev.c
 @@ -3967,6 +3967,9 @@ static enum gro_result dev_gro_receive(s

target/linux/generic/patches-4.0/680-net-skip-gro-for-otherhost-packets.patch

@@ -1,3 +1,17 @@
+Subject: NET: skip GRO for otherhost packets
+
+For network drivers using napi_gro_receive, packets are run through GRO,
+even when the destination MAC address does not match, and they're supposed
+to be delivered to another host behind a different bridge port.
+
+This can be very expensive, because for drivers without TSO or scatter-
+gather, this can only be undone by copying the skb and checksumming it
+again.
+
+Fix this by leaving skbs with PACKET_OTHERHOST untouched.
+
+Signed-off-by: Felix Fietkau <nbd@openwrt.org>
+
 --- a/net/core/dev.c
 +++ b/net/core/dev.c
 @@ -4005,6 +4005,9 @@ static enum gro_result dev_gro_receive(s