caif: Use link layer MTU instead of fixed MTU
Previously CAIF supported maximum transfer size of ~4050.
The transfer size is now calculated dynamically based on the
link layers mtu size.
Signed-off-by: Sjur Braendeland@stericsson.com
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/caif/cfdgml.c b/net/caif/cfdgml.c
index 32d9f0d..ed9d53a 100644
--- a/net/caif/cfdgml.c
+++ b/net/caif/cfdgml.c
@@ -17,6 +17,7 @@
#define DGM_FLOW_OFF 0x81
#define DGM_FLOW_ON 0x80
#define DGM_CTRL_PKT_SIZE 1
+#define DGM_MTU 1500
static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt);
static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt);
@@ -89,6 +90,10 @@
if (!cfsrvl_ready(service, &ret))
return ret;
+ /* STE Modem cannot handle more than 1500 bytes datagrams */
+ if (cfpkt_getlen(pkt) > DGM_MTU)
+ return -EMSGSIZE;
+
cfpkt_add_head(pkt, &zero, 4);
/* Add info for MUX-layer to route the packet out. */