From fa655ce196ad82e3b8664dcd0ba78328ecaa9a58 Mon Sep 17 00:00:00 2001
From: Daniel Campora <daniel@wipy.io>
Date: Sun, 5 Jul 2015 22:26:12 +0200
Subject: [PATCH] cc3200: Improve interrupt handling and fix bug in
 HAL_Delay().

---
 cc3200/hal/cc3200_hal.c  | 26 +++++++++++++++++---------
 cc3200/misc/mpcallback.c | 14 +++++++-------
 cc3200/mods/modutime.c   |  5 ++++-
 cc3200/mods/pybuart.c    |  8 ++++----
 4 files changed, 32 insertions(+), 21 deletions(-)

diff --git a/cc3200/hal/cc3200_hal.c b/cc3200/hal/cc3200_hal.c
index 3860641161..671af3cf9c 100644
--- a/cc3200/hal/cc3200_hal.c
+++ b/cc3200/hal/cc3200_hal.c
@@ -45,6 +45,7 @@
 #include "mpexception.h"
 #include "telnet.h"
 #include "pybuart.h"
+#include "utils.h"
 
 #ifdef USE_FREERTOS
 #include "FreeRTOS.h"
@@ -107,16 +108,23 @@ uint32_t HAL_GetTick(void) {
 }
 
 void HAL_Delay(uint32_t delay) {
-#ifdef USE_FREERTOS
-    vTaskDelay (delay / portTICK_PERIOD_MS);
-#else
-    uint32_t start = HAL_tickCount;
-    // Wraparound of tick is taken care of by 2's complement arithmetic.
-    while (HAL_tickCount - start < delay) {
-        // Enter sleep mode, waiting for (at least) the SysTick interrupt.
-        __WFI();
+    // only if we are not within interrupt context
+    if ((HAL_NVIC_INT_CTRL_REG & HAL_VECTACTIVE_MASK) == 0) {
+        #ifdef USE_FREERTOS
+            vTaskDelay (delay / portTICK_PERIOD_MS);
+        #else
+            uint32_t start = HAL_tickCount;
+            // wraparound of tick is taken care of by 2's complement arithmetic.
+            while (HAL_tickCount - start < delay) {
+                // enter sleep mode, waiting for (at least) the SysTick interrupt.
+                __WFI();
+            }
+        #endif
+    } else {
+        for (int ms = 1; ms <= delay; ms++) {
+            UtilsDelay(UTILS_DELAY_US_TO_COUNT(ms * 1000));
+        }
     }
-#endif
 }
 
 void mp_hal_set_interrupt_char (int c) {
diff --git a/cc3200/misc/mpcallback.c b/cc3200/misc/mpcallback.c
index 5c23abe66c..35342a0ccf 100644
--- a/cc3200/misc/mpcallback.c
+++ b/cc3200/misc/mpcallback.c
@@ -24,6 +24,8 @@
  * THE SOFTWARE.
  */
 
+#include "std.h"
+
 #include "py/mpconfig.h"
 #include MICROPY_HAL_H
 #include "py/obj.h"
@@ -124,10 +126,8 @@ uint mpcallback_translate_priority (uint priority) {
 void mpcallback_handler (mp_obj_t self_in) {
     mpcallback_obj_t *self = self_in;
     if (self && self->handler != mp_const_none) {
-        // disable interrupts to avoid nesting
-        uint primsk = disable_irq();
         // when executing code within a handler we must lock the GC to prevent
-        // any memory allocations.  We must also catch any exceptions.
+        // any memory allocations.
         gc_lock();
         nlr_buf_t nlr;
         if (nlr_push(&nlr) == 0) {
@@ -138,13 +138,13 @@ void mpcallback_handler (mp_obj_t self_in) {
             // uncaught exception; disable the callback so that it doesn't run again
             self->methods->disable (self->parent);
             self->handler = mp_const_none;
-            // printing an exception here will cause a stack overflow that will end up in
-            // a hard fault, so is better to signal the uncaught (probably non-recoverable)
-            // exception by blinking the system led instead.
+            // signal the error using the heart beat led and print an
+            // exception message as well
             mperror_signal_error();
+            printf("Uncaught exception in callback handler\n");
+            mp_obj_print_exception(&mp_plat_print, (mp_obj_t)nlr.ret_val);
         }
         gc_unlock();
-        enable_irq(primsk);
     }
 }
 
diff --git a/cc3200/mods/modutime.c b/cc3200/mods/modutime.c
index f828fca9ae..d69e5c4e2e 100644
--- a/cc3200/mods/modutime.c
+++ b/cc3200/mods/modutime.c
@@ -125,7 +125,10 @@ MP_DEFINE_CONST_FUN_OBJ_1(time_mktime_obj, time_mktime);
 /// \function sleep(seconds)
 /// Sleep for the given number of seconds.
 STATIC mp_obj_t time_sleep(mp_obj_t seconds_o) {
-    HAL_Delay(mp_obj_get_int(seconds_o) * 1000);
+    int32_t sleep_s = mp_obj_get_int(seconds_o);
+    if (sleep_s > 0) {
+        HAL_Delay(sleep_s * 1000);
+    }
     return mp_const_none;
 }
 MP_DEFINE_CONST_FUN_OBJ_1(time_sleep_obj, time_sleep);
diff --git a/cc3200/mods/pybuart.c b/cc3200/mods/pybuart.c
index 41a0a2ec34..f4ac2881a1 100644
--- a/cc3200/mods/pybuart.c
+++ b/cc3200/mods/pybuart.c
@@ -89,8 +89,8 @@
 /******************************************************************************
  DEFINE CONSTANTS
  ******************************************************************************/
-#define PYBUART_TX_WAIT_MS                  1
-#define PYBUART_TX_MAX_TIMEOUT_MS           5
+#define PYBUART_TX_WAIT_US                      (50)
+#define PYBUART_TX_MAX_TIMEOUT_MS               (5)
 
 /******************************************************************************
  DECLARE PRIVATE FUNCTIONS
@@ -156,10 +156,10 @@ bool uart_tx_char(pyb_uart_obj_t *self, int c) {
     uint32_t timeout = 0;
 
     while (!MAP_UARTCharPutNonBlocking(self->reg, c)) {
-        if (timeout++ > (PYBUART_TX_MAX_TIMEOUT_MS / PYBUART_TX_WAIT_MS)) {
+        if (timeout++ > ((PYBUART_TX_MAX_TIMEOUT_MS * 1000) / PYBUART_TX_WAIT_US)) {
             return false;
         }
-        HAL_Delay (PYBUART_TX_WAIT_MS);
+        UtilsDelay(UTILS_DELAY_US_TO_COUNT(PYBUART_TX_WAIT_US));
     }
     return true;
 }