zero copy HCI as a config option

Author: paul-szczepanek-arm

features/FEATURE_BLE/targets/TARGET_CORDIO/driver/CordioHCITransportDriver.h

@@ -55,7 +55,8 @@ class CordioHCITransportDriver {
      * packet, ACL packet or EVT packet. Depending on the type of transport
      * it can prefix the packet itself.
      * @param len Number of bytes to transmit.
-     * @param pData Pointer to the data to transmit. This is an WSF buffer and we receive ownership.
+     * @param pData Pointer to the data to transmit. This is an WSF buffer
+     * and if CORDIO_ZERO_COPY_HCI is enabled we receive ownership.
      *
      * @return The number of bytes which have been transmited.
      */

features/FEATURE_BLE/targets/TARGET_CORDIO/stack_adaptation/hci_tr.c

@@ -66,12 +66,15 @@ void hciTrSendAclData(void *pContext, uint8_t *pData)
   HCI_PDUMP_TX_ACL(len, pData);
 
   /* transmit ACL header and data */
-  if (hciDrvWrite(HCI_ACL_TYPE, len, pData) != len)
+  if (hciDrvWrite(HCI_ACL_TYPE, len, pData) == len)
   {
-    /* transport failure */
-    WSF_ASSERT(0);
+#if CORDIO_ZERO_COPY_HCI
+      /* pData is not freed as the hciDrvWrite took ownership of the WSF buffer */
+#else
+      /* free buffer */
+      WsfMsgFree(pData);
+#endif // CORDIO_ZERO_COPY_HCI
   }
-  /* pData is not freed as the hciDrvWrite took ownership of the WSF buffer */
 }
 
 
@@ -96,13 +99,16 @@ void hciTrSendCmd(uint8_t *pData)
   /* dump event for protocol analysis */
   HCI_PDUMP_CMD(len, pData);
 
-  /* transmit ACL header and data (releases the ownership of the WSF buffer containing pData) */
-  if (hciDrvWrite(HCI_CMD_TYPE, len, pData) != len)
+  /* transmit ACL header and data */
+  if (hciDrvWrite(HCI_CMD_TYPE, len, pData) == len)
   {
-    /* transport failure */
-    WSF_ASSERT(0);
+#if CORDIO_ZERO_COPY_HCI
+      /* pData is not freed as the hciDrvWrite took ownership of the WSF buffer */
+#else
+      /* free buffer */
+      WsfMsgFree(pData);
+#endif // CORDIO_ZERO_COPY_HCI
   }
-  /* pData is not freed as the hciDrvWrite took ownership of the WSF buffer */
 }
 
 

features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NORDIC_CORDIO/TARGET_NRF5x/NRFCordioHCITransportDriver.h

@@ -51,7 +51,8 @@ class NRFCordioHCITransportDriver : public cordio::CordioHCITransportDriver {
      * packet, ACL packet or EVT packet. Depending on the type of transport
      * it can prefix the packet itself.
      * @param len Number of bytes to transmit.
-     * @param pData Pointer to the data to transmit. This is an WSF buffer and we receive ownership.
+     * @param pData Pointer to the data to transmit. This is an WSF buffer
+     * and if CORDIO_ZERO_COPY_HCI is enabled we receive ownership.
      *
      * @return The number of bytes which have been transmited.
      */

features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NORDIC_CORDIO/TARGET_NRF5x/mbed_lib.json

@@ -1,5 +1,12 @@
 {
     "name": "cordio-nordic-ll",
+    "config": {
+        "zero-copy-hci": {
+            "help": "messages sent between Host and Controller are passed directly without copying if enabled. WSF messages ownership is trasfered to the callee.",
+            "value": 0,
+            "macro_name": "CORDIO_ZERO_COPY_HCI"
+        }
+    },
     "macros": [
         "INIT_BROADCASTER",
         "INIT_OBSERVER",