net: ipa: rename endpoint->trans_tre_max

The trans_tre_max field of the IPA endpoint structure is only used
to limit the number of fragments allowed for an SKB being prepared
for transmission.  Recognizing that, rename the field skb_frag_max,
and reduce its value by 1.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ipa/ipa_endpoint.c

@@ -1020,7 +1020,7 @@ int ipa_endpoint_skb_tx(struct ipa_endpoint *endpoint, struct sk_buff *skb)
 	 * If not, see if we can linearize it before giving up.
 	 */
 	nr_frags = skb_shinfo(skb)->nr_frags;
-	if (1 + nr_frags > endpoint->trans_tre_max) {
+	if (nr_frags > endpoint->skb_frag_max) {
 		if (skb_linearize(skb))
 			return -E2BIG;
 		nr_frags = 0;
@@ -1721,7 +1721,7 @@ static void ipa_endpoint_setup_one(struct ipa_endpoint *endpoint)
 	if (endpoint->ee_id != GSI_EE_AP)
 		return;
 
-	endpoint->trans_tre_max = gsi->channel[channel_id].trans_tre_max;
+	endpoint->skb_frag_max = gsi->channel[channel_id].trans_tre_max - 1;
 	if (!endpoint->toward_ipa) {
 		/* RX transactions require a single TRE, so the maximum
 		 * backlog is the same as the maximum outstanding TREs.

drivers/net/ipa/ipa_endpoint.h

@@ -142,7 +142,7 @@ enum ipa_replenish_flag {
  * @endpoint_id:	IPA endpoint number
  * @toward_ipa:		Endpoint direction (true = TX, false = RX)
  * @config:		Default endpoint configuration
- * @trans_tre_max:	Maximum number of TRE descriptors per transaction
+ * @skb_frag_max:	Maximum allowed number of TX SKB fragments
  * @evt_ring_id:	GSI event ring used by the endpoint
  * @netdev:		Network device pointer, if endpoint uses one
  * @replenish_flags:	Replenishing state flags
@@ -157,7 +157,7 @@ struct ipa_endpoint {
 	bool toward_ipa;
 	struct ipa_endpoint_config config;
 
-	u32 trans_tre_max;
+	u32 skb_frag_max;	/* Used for netdev TX only */
 	u32 evt_ring_id;
 
 	/* Net device this endpoint is associated with, if any */