DO NOT MERGE - Remove ACL connection reference counting

In addition to maintaining ACL link control blocks, which carry a
"in_use" flag, ACL links are reference counted in the num_acl links
variable.

The reference counting is thrown off when a SM connection initiated for
pairing is followed up by a GATT connection after pairing completes. The
2nd connection is counted against num_acl, even so other parts of the
code recognize the connection as a duplicate ACL connection to the same
BDA.

This patch removes the unecessary reference counting and relies on the
control block status instead, which is correctly maintained.

The BTM_BUSY_LEVEL_CHANGE_INCLUDED flag encapsulating the num_acl
tracking should be removed in the future.

Bug: 19019189
Change-Id: I4cc88c24f1c4d1273361d879bc62e9fade3f3ee9

3 files changed, 6 insertions, 20 deletions

diff --git a/stack/btm/btm_acl.c b/stack/btm/btm_acl.c
index fa742e58d..0e33bf802 100644
--- a/stack/btm/btm_acl.c
+++ b/stack/btm/btm_acl.c
@@ -525,18 +525,9 @@ void btm_acl_update_busy_level (tBTM_BLI_EVENT event)
     {
         case BTM_BLI_ACL_UP_EVT:
             BTM_TRACE_DEBUG ("BTM_BLI_ACL_UP_EVT");
-            btm_cb.num_acl++;
             break;
         case BTM_BLI_ACL_DOWN_EVT:
-            if (btm_cb.num_acl)
-            {
-                btm_cb.num_acl--;
-                BTM_TRACE_DEBUG ("BTM_BLI_ACL_DOWN_EVT", btm_cb.num_acl);
-            }
-            else
-            {
-                BTM_TRACE_ERROR ("BTM_BLI_ACL_DOWN_EVT issued, but num_acl already zero !!!");
-            }
+            BTM_TRACE_DEBUG ("BTM_BLI_ACL_DOWN_EVT");
             break;
         case BTM_BLI_PAGE_EVT:
             BTM_TRACE_DEBUG ("BTM_BLI_PAGE_EVT");
@@ -568,7 +559,7 @@ void btm_acl_update_busy_level (tBTM_BLI_EVENT event)
     if (btm_cb.is_paging || btm_cb.is_inquiry)
         busy_level = 10;
     else
-        busy_level = (UINT8)btm_cb.num_acl;
+        busy_level = BTM_GetNumAclLinks();
 
     if ((busy_level != btm_cb.busy_level) ||(old_inquiry_state != btm_cb.is_inquiry))
     {
@@ -1648,6 +1639,7 @@ void btm_establish_continue (tACL_CONN *p_acl_cb)
 
             (*btm_cb.p_bl_changed_cb)(&evt_data);
         }
+
         btm_acl_update_busy_level (BTM_BLI_ACL_UP_EVT);
 #else
         if (btm_cb.p_acl_changed_cb)
@@ -2132,9 +2124,6 @@ BOOLEAN BTM_IsAclConnectionUp (BD_ADDR remote_bda, tBT_TRANSPORT transport)
 *******************************************************************************/
 UINT16 BTM_GetNumAclLinks (void)
 {
-#if (defined(BTM_BUSY_LEVEL_CHANGE_INCLUDED) && BTM_BUSY_LEVEL_CHANGE_INCLUDED == TRUE)
-    return(UINT16)btm_cb.num_acl;
-#else
     tACL_CONN   *p = &btm_cb.acl_db[0];
     UINT16      xx, yy;
     BTM_TRACE_DEBUG ("BTM_GetNumAclLinks");
@@ -2145,7 +2134,6 @@ UINT16 BTM_GetNumAclLinks (void)
     }
 
     return(yy);
-#endif
 }
 
 /*******************************************************************************
diff --git a/stack/btm/btm_int.h b/stack/btm/btm_int.h
index fcb17bb5c..7032177f2 100644
--- a/stack/btm/btm_int.h
+++ b/stack/btm/btm_int.h
@@ -916,7 +916,6 @@ typedef struct
     UINT8                   acl_disc_reason;
     UINT8                   trace_level;
 #if (defined(BTM_BUSY_LEVEL_CHANGE_INCLUDED) && BTM_BUSY_LEVEL_CHANGE_INCLUDED == TRUE)
-    UINT8                   num_acl;    /* num of active ACL links */
     UINT8                   busy_level; /* the current busy level */
     BOOLEAN                 is_paging;  /* TRUE, if paging is in progess */
     BOOLEAN                 is_inquiry; /* TRUE, if inquiry is in progess */
diff --git a/stack/btm/btm_pm.c b/stack/btm/btm_pm.c
index 76bfc048b..ffa4acf57 100644
--- a/stack/btm/btm_pm.c
+++ b/stack/btm/btm_pm.c
@@ -1020,9 +1020,9 @@ BOOLEAN btm_pm_device_in_active_or_sniff_mode(void)
     /* The active state is the highest state-includes connected device and sniff mode*/
 
     /* Covers active and sniff modes */
-    if (btm_cb.num_acl > 0)
+    if (BTM_GetNumAclLinks() > 0)
     {
-        BTM_TRACE_DEBUG("btm_pm_device_in_active_or_sniff_mode-acl:%d", btm_cb.num_acl);
+        BTM_TRACE_DEBUG("%s() - ACL links: %d", __FUNCTION__, BTM_GetNumAclLinks());
         return TRUE;
     }
 
@@ -1030,8 +1030,7 @@ BOOLEAN btm_pm_device_in_active_or_sniff_mode(void)
     /* Check BLE states */
     if (btm_ble_get_conn_st() != BLE_CONN_IDLE)
     {
-        BTM_TRACE_DEBUG("btm_pm_device_in_active_or_sniff_mode- BLE state: %x",
-                        btm_ble_get_conn_st());
+        BTM_TRACE_DEBUG("%s() - BLE state: %x", __FUNCTION__, btm_ble_get_conn_st());
         return TRUE;
     }
 #endif