Fix for bluedroid sometimes holding kernel wake lock inadvertendly

Two problems
- sometimes bluedroid will not issue upio_set to release kernel
wake lock. Timeout would fire but would not release lpm driver
cmd to release kernel wake lock
- lpm wake lock was not being extended as bluedroid would
constantly use the interface.

Bug: 21063567
Change-Id: I898508493bbf7b8c2ddb79d7c7398b6900ade12c

1 files changed, 47 insertions, 16 deletions

diff --git a/src/upio.c b/src/upio.c
index 2d705e3..436b7e4 100644
--- a/src/upio.c
+++ b/src/upio.c
@@ -195,9 +195,43 @@ static void proc_btwrite_timeout(union sigval arg)
 {
     UPIODBG("..%s..", __FUNCTION__);
     lpm_proc_cb.btwrite_active = FALSE;
+    /* drive LPM down; this timer should fire only when BT is awake; */
+    upio_set(UPIO_BT_WAKE, UPIO_DEASSERT, 1);
 }
 #endif
 
+/******************************************************************************
+ **
+ ** Function      upio_start_stop_timer
+ **
+ ** Description   Arm user space timer in case lpm is left asserted
+ **
+ ** Returns       None
+ **
+ *****************************************************************************/
+void upio_start_stop_timer(int action) {
+    struct itimerspec ts;
+
+    if (action == UPIO_ASSERT) {
+        lpm_proc_cb.btwrite_active = TRUE;
+        if (lpm_proc_cb.timer_created == TRUE) {
+            ts.it_value.tv_sec = PROC_BTWRITE_TIMER_TIMEOUT_MS/1000;
+            ts.it_value.tv_nsec = 1000000*(PROC_BTWRITE_TIMER_TIMEOUT_MS%1000);
+            ts.it_interval.tv_sec = 0;
+            ts.it_interval.tv_nsec = 0;
+        }
+    } else {
+        /* unarm timer if writing 0 to lpm; reduce unnecessary user space wakeup */
+        memset(&ts, 0, sizeof(ts));
+    }
+
+    if (timer_settime(lpm_proc_cb.timer_id, 0, &ts, 0) == 0) {
+        UPIODBG("%s : timer_settime success", __FUNCTION__);
+    } else {
+        UPIODBG("%s : timer_settime failed", __FUNCTION__);
+    }
+}
+
 /*****************************************************************************
 **   UPIO Interface Functions
 *****************************************************************************/
@@ -331,6 +365,8 @@ void upio_set(uint8_t pio, uint8_t action, uint8_t polarity)
     char buffer;
 #endif
 
+    UPIODBG("%s : pio %d action %d, polarity %d", __FUNCTION__, pio, action, polarity);
+
     switch (pio)
     {
         case UPIO_LPM_MODE:
@@ -410,7 +446,7 @@ void upio_set(uint8_t pio, uint8_t action, uint8_t polarity)
                 UPIODBG("BT_WAKE is %s already", lpm_state[action]);
 
 #if (BT_WAKE_VIA_PROC == TRUE)
-                if (lpm_proc_cb.btwrite_active == TRUE)
+                if (lpm_proc_cb.btwrite_active == TRUE) {
                     /*
                      * The proc btwrite node could have not been updated for
                      * certain time already due to heavy downstream path flow.
@@ -420,8 +456,13 @@ void upio_set(uint8_t pio, uint8_t action, uint8_t polarity)
                      * a 10sec internal in-activity timeout timer before it
                      * attempts to deassert BT_WAKE line.
                      */
-#endif
+                    /* re-arm user space timer */
+                    upio_start_stop_timer(action);
+                    return;
+                }
+#else
                 return;
+#endif
             }
 
             upio_state[UPIO_BT_WAKE] = action;
@@ -464,23 +505,13 @@ void upio_set(uint8_t pio, uint8_t action, uint8_t polarity)
 #if (PROC_BTWRITE_TIMER_TIMEOUT_MS != 0)
             else
             {
-                lpm_proc_cb.btwrite_active = TRUE;
-
-                if (lpm_proc_cb.timer_created == TRUE)
-                {
-                    struct itimerspec ts;
-
-                    ts.it_value.tv_sec = PROC_BTWRITE_TIMER_TIMEOUT_MS/1000;
-                    ts.it_value.tv_nsec = 1000000*(PROC_BTWRITE_TIMER_TIMEOUT_MS%1000);
-                    ts.it_interval.tv_sec = 0;
-                    ts.it_interval.tv_nsec = 0;
-
-                    timer_settime(lpm_proc_cb.timer_id, 0, &ts, 0);
-                }
+                /* arm user space timer based on action */
+                upio_start_stop_timer(action);
             }
 #endif
 
-            UPIODBG("proc btwrite assertion");
+            UPIODBG("%s: proc btwrite assertion, buffer: %c, timer_armed %d %d",
+                    __FUNCTION__, buffer, lpm_proc_cb.btwrite_active, lpm_proc_cb.timer_created);
 
             if (fd >= 0)
                 close(fd);