OTAP: better handle delay for process scratchpad

The process scratchpad call is finished only when the connection
with the stack is available again.
Wait for up to 60 sec for the gateway to answer.

lib/wpc/wpc.c

@@ -14,6 +14,7 @@
 
 #include "wpc.h"  // For DEFAULT_BITRATE
 #include "wpc_internal.h"
+#include "platform.h"  // For Platform_get_timestamp_ms_epoch()
 
 /**
  * \brief   Macro to convert dual_mcu return code
@@ -31,6 +32,13 @@
         ret;                                    \
     })
 
+/** \brief   Timeout to get a valid stack response after
+ *           a stop stack. It can be quite long in case of
+ *           the bootloader is processing a scratchpad
+ *           (especially from an external memory)
+*/
+#define TIMEOUT_AFTER_STOP_STACK_S 60
+
 app_res_e WPC_initialize(char * port_name, unsigned long bitrate)
 {
     return WPC_Int_initialize(port_name, bitrate) == 0 ? APP_RES_OK : APP_RES_INTERNAL_ERROR;
@@ -448,23 +456,23 @@ app_res_e WPC_get_sink_cost(uint8_t * cost_p)
     return convert_error_code(SINK_COST_ERROR_CODE_LUT, res);
 }
 
-// Define the maximum number of attempt to get status after a
-// stop or start of stack
-#define MAX_GET_STATUS_ATTEMPT 20
-
-static bool get_statck_status()
+static bool get_statck_status(uint16_t timeout_s)
 {
     uint8_t status;
-    uint8_t max_attempt = MAX_GET_STATUS_ATTEMPT;
+    app_res_e res = APP_RES_INTERNAL_ERROR;
 
-    while (WPC_get_stack_status(&status) != APP_RES_OK && max_attempt-- > 0)
+    // Compute timeout
+    unsigned long long timeout = Platform_get_timestamp_ms_epoch() + timeout_s * 1000;
+
+    while (res != APP_RES_OK && Platform_get_timestamp_ms_epoch() < timeout)
     {
+        res = WPC_get_stack_status(&status);
         LOGD("Cannot get status after start/stop, try again...\n");
     }
 
-    if (max_attempt == 0)
+    if (res != APP_RES_OK)
     {
-        LOGE("Cannot get stack status after %d attempts\n", MAX_GET_STATUS_ATTEMPT);
+        LOGE("Cannot get stack status after %d seconds\n", timeout_s);
         return false;
     }
 
@@ -473,6 +481,13 @@ static bool get_statck_status()
 app_res_e WPC_start_stack(void)
 {
     int res = msap_stack_start_request(0);
+
+    if (res < 0)
+    {
+        // Error in communication
+        return APP_RES_INTERNAL_ERROR;
+    }
+
     if ((res & 0x1) == 0x01)
     {
         return APP_RES_STACK_ALREADY_STARTED;
@@ -495,10 +510,10 @@ app_res_e WPC_start_stack(void)
     }
 
     // A start of the stack shouldn't create any interruption
-    // of service but let's poll for it to be symetric with stop
+    // of service but let's poll for it to be symmetric with stop
     // and for some reason it was seen on some platforms that the
     // first request following a start is lost
-    if (!get_statck_status())
+    if (!get_statck_status(2))
     {
         return APP_RES_INTERNAL_ERROR;
     }
@@ -510,6 +525,12 @@ app_res_e WPC_stop_stack(void)
 {
     int res = msap_stack_stop_request();
 
+    if (res < 0)
+    {
+        // Error in communication
+        return APP_RES_INTERNAL_ERROR;
+    }
+
     if (res == 1)
     {
         return APP_RES_STACK_ALREADY_STOPPED;
@@ -521,7 +542,8 @@ app_res_e WPC_stop_stack(void)
 
     // A stop of the stack will reboot the device
     // Wait for the stack to be up again
-    if (!get_statck_status())
+    // It can be quite long in case a scratchpad is processed
+    if (!get_statck_status(TIMEOUT_AFTER_STOP_STACK_S))
     {
         return APP_RES_INTERNAL_ERROR;
     }