net: wwan: iosm: correct link-id handling

Link ID to be kept intact with MBIM session ID
Ex: ID 0 should be associated to MBIM session ID 0.
Reported-by: Loic Poulain <loic.poulain@linaro.org>
Signed-off-by: M Chetan Kumar <m.chetan.kumar@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/wwan/iosm/iosm_ipc_imem_ops.c

@@ -24,7 +24,7 @@ int ipc_imem_sys_wwan_open(struct iosm_imem *ipc_imem, int if_id)
 		return -EIO;
 	}
 
-	return ipc_mux_open_session(ipc_imem->mux, if_id - 1);
+	return ipc_mux_open_session(ipc_imem->mux, if_id);
 }
 
 /* Release a net link to CP. */
@@ -33,7 +33,7 @@ void ipc_imem_sys_wwan_close(struct iosm_imem *ipc_imem, int if_id,
 {
 	if (ipc_imem->mux && if_id >= IP_MUX_SESSION_START &&
 	    if_id <= IP_MUX_SESSION_END)
-		ipc_mux_close_session(ipc_imem->mux, if_id - 1);
+		ipc_mux_close_session(ipc_imem->mux, if_id);
 }
 
 /* Tasklet call to do uplink transfer. */
@@ -76,7 +76,7 @@ int ipc_imem_sys_wwan_transmit(struct iosm_imem *ipc_imem,
 	}
 
 	/* Route the UL packet through IP MUX Layer */
-	ret = ipc_mux_ul_trigger_encode(ipc_imem->mux, if_id - 1, skb);
+	ret = ipc_mux_ul_trigger_encode(ipc_imem->mux, if_id, skb);
 out:
 	return ret;
 }

drivers/net/wwan/iosm/iosm_ipc_imem_ops.h

@@ -27,11 +27,11 @@
 #define BOOT_CHECK_DEFAULT_TIMEOUT 400
 
 /* IP MUX channel range */
-#define IP_MUX_SESSION_START 1
-#define IP_MUX_SESSION_END 8
+#define IP_MUX_SESSION_START 0
+#define IP_MUX_SESSION_END 7
 
 /* Default IP MUX channel */
-#define IP_MUX_SESSION_DEFAULT	1
+#define IP_MUX_SESSION_DEFAULT	0
 
 /**
  * ipc_imem_sys_port_open - Open a port link to CP.

drivers/net/wwan/iosm/iosm_ipc_mux_codec.c

@@ -288,7 +288,7 @@ static int ipc_mux_net_receive(struct iosm_mux *ipc_mux, int if_id,
 	/* Pass the packet to the netif layer. */
 	dest_skb->priority = service_class;
 
-	return ipc_wwan_receive(wwan, dest_skb, false, if_id + 1);
+	return ipc_wwan_receive(wwan, dest_skb, false, if_id);
 }
 
 /* Decode Flow Credit Table in the block */

drivers/net/wwan/iosm/iosm_ipc_wwan.c

@@ -252,8 +252,8 @@ int ipc_wwan_receive(struct iosm_wwan *ipc_wwan, struct sk_buff *skb_arg,
 
 	skb->pkt_type = PACKET_HOST;
 
-	if (if_id < (IP_MUX_SESSION_START - 1) ||
-	    if_id > (IP_MUX_SESSION_END - 1)) {
+	if (if_id < IP_MUX_SESSION_START ||
+	    if_id > IP_MUX_SESSION_END) {
 		ret = -EINVAL;
 		goto free;
 	}