Send BLE controller commands from tasks running on core 0 only.

* This fixes noticable delays when controller commands originte from core 1 tasks.
  Most noticable when starting advertising.

  This patch ensures that sending commands to the controller only executes on core 0.

* Also improves overall performance slightly.

* Removes previous advertising start delay fix.

Author: h2zero

src/NimBLEAdvertising.cpp

@@ -227,11 +227,6 @@ void NimBLEAdvertising::start() {
     if(pServer != nullptr) {
         if(!pServer->m_gattsStarted){
             pServer->start();
-            // When the server instance is created it resets GATT which
-            // seems to put the controller in a sleep loop? This causes a delay when
-            // advertising is started the first time. To avoid this we call ble_gap_adv_stop
-            // to get the controller ready.
-            ble_gap_adv_stop();
         } else if(pServer->getConnectedCount() >= NIMBLE_MAX_CONNECTIONS) {
             NIMBLE_LOGW(LOG_TAG, "Max connections reached - not advertising");
             return;

src/esp-hci/src/esp_nimble_hci.c

@@ -30,6 +30,7 @@
 #include "esp_bt.h"
 #include "freertos/semphr.h"
 #include "esp_compiler.h"
+#include "esp_ipc.h"
 
 #define NIMBLE_VHCI_TIMEOUT_MS  2000
 
@@ -78,21 +79,29 @@ void ble_hci_trans_cfg_hs(ble_hci_trans_rx_cmd_fn *cmd_cb,
     ble_hci_rx_acl_hs_arg = acl_arg;
 }
 
+void ble_hci_trans_hs_cmd_tx_on_core_0(void *arg)
+{
+    uint8_t *cmd = arg;
+    uint16_t len = BLE_HCI_CMD_HDR_LEN + cmd[3] + 1;
+    esp_vhci_host_send_packet(cmd, len);
+}
 
 int ble_hci_trans_hs_cmd_tx(uint8_t *cmd)
 {
-    uint16_t len;
     uint8_t rc = 0;
 
     assert(cmd != NULL);
     *cmd = BLE_HCI_UART_H4_CMD;
-    len = BLE_HCI_CMD_HDR_LEN + cmd[3] + 1;
     if (!esp_vhci_host_check_send_available()) {
         ESP_LOGD(TAG, "Controller not ready to receive packets");
     }
 
     if (xSemaphoreTake(vhci_send_sem, NIMBLE_VHCI_TIMEOUT_MS / portTICK_PERIOD_MS) == pdTRUE) {
-        esp_vhci_host_send_packet(cmd, len);
+        if (xPortGetCoreID() != 0) {
+            esp_ipc_call_blocking(0, ble_hci_trans_hs_cmd_tx_on_core_0, cmd);
+        } else {
+            ble_hci_trans_hs_cmd_tx_on_core_0(cmd);
+        }
     } else {
         rc = BLE_HS_ETIMEOUT_HCI;
     }
@@ -111,27 +120,37 @@ int ble_hci_trans_ll_evt_tx(uint8_t *hci_ev)
     return rc;
 }
 
+void ble_hci_trans_hs_acl_tx_on_core_0(void *arg)
+{
+    uint8_t data[MYNEWT_VAL(BLE_ACL_BUF_SIZE) + 1];
+    struct os_mbuf *om = arg;
+    uint16_t len = 1 + OS_MBUF_PKTLEN(om);
+
+    data[0] = BLE_HCI_UART_H4_ACL;
+    os_mbuf_copydata(om, 0, OS_MBUF_PKTLEN(om), &data[1]);
+
+    esp_vhci_host_send_packet(data, len);
+}
+
 int ble_hci_trans_hs_acl_tx(struct os_mbuf *om)
 {
-    uint16_t len = 0;
-    uint8_t data[MYNEWT_VAL(BLE_ACL_BUF_SIZE) + 1], rc = 0;
+    uint8_t rc = 0;
     /* If this packet is zero length, just free it */
     if (OS_MBUF_PKTLEN(om) == 0) {
         os_mbuf_free_chain(om);
         return 0;
     }
-    data[0] = BLE_HCI_UART_H4_ACL;
-    len++;
 
     if (!esp_vhci_host_check_send_available()) {
         ESP_LOGD(TAG, "Controller not ready to receive packets");
     }
 
-    os_mbuf_copydata(om, 0, OS_MBUF_PKTLEN(om), &data[1]);
-    len += OS_MBUF_PKTLEN(om);
-
     if (xSemaphoreTake(vhci_send_sem, NIMBLE_VHCI_TIMEOUT_MS / portTICK_PERIOD_MS) == pdTRUE) {
-        esp_vhci_host_send_packet(data, len);
+        if (xPortGetCoreID() != 0) {
+            esp_ipc_call_blocking(0, ble_hci_trans_hs_acl_tx_on_core_0, om);
+        } else {
+            ble_hci_trans_hs_acl_tx_on_core_0(om);
+        }
     } else {
         rc = BLE_HS_ETIMEOUT_HCI;
     }