caif: performance bugfix - allow radio stack to prioritize packets.

In the CAIF Payload message the Packet Type indication must be set to
    UNCLASSIFIED in order to allow packet prioritization in the modem's
    network stack. Otherwise TCP-Ack is not prioritized in the modems
    transmit queue.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/caif/cfdgml.c

@@ -13,6 +13,7 @@
 #include <net/caif/cfsrvl.h>
 #include <net/caif/cfpkt.h>
 
+
 #define container_obj(layr) ((struct cfsrvl *) layr)
 
 #define DGM_CMD_BIT  0x80
@@ -83,6 +84,7 @@ static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt)
 
 static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt)
 {
+	u8 packet_type;
 	u32 zero = 0;
 	struct caif_payload_info *info;
 	struct cfsrvl *service = container_obj(layr);
@@ -94,7 +96,9 @@ static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt)
 	if (cfpkt_getlen(pkt) > DGM_MTU)
 		return -EMSGSIZE;
 
-	cfpkt_add_head(pkt, &zero, 4);
+	cfpkt_add_head(pkt, &zero, 3);
+	packet_type = 0x08; /* B9 set - UNCLASSIFIED */
+	cfpkt_add_head(pkt, &packet_type, 1);
 
 	/* Add info for MUX-layer to route the packet out. */
 	info = cfpkt_info(pkt);