ElectronSerialPipe: correctly handle buffer overflow

particle-iot · Oct 16, 2016 · 428835a · 428835a
1 parent ecd176b
commit 428835a
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Showing 3 changed files with 14 additions and 7 deletions.
diff --git a/hal/src/electron/modem/electronserialpipe_hal.cpp b/hal/src/electron/modem/electronserialpipe_hal.cpp
@@ -218,15 +218,15 @@ void ElectronSerialPipe::rxIrqBuf(void)
         char c = USART_ReceiveData(USART3);
         _pipeRx.putc(c);
     } else {
-        /* TODO: Handle overflow?
-         * We should not read USART3->RDR register in order to
-         * signal to the modem that we are not ready to receive,
-         * then try to process and free the buffer.
-         */
-        (void)USART_ReceiveData(USART3);
+        USART_ITConfig(USART3, USART_IT_RXNE, DISABLE);
     }
 }
 
+void ElectronSerialPipe::rxResume(void)
+{
+    USART_ITConfig(USART3, USART_IT_RXNE, ENABLE);
+}
+
 /*******************************************************************************
  * Function Name  : HAL_USART3_Handler
  * Description    : This function handles USART3 global interrupt request.

diff --git a/hal/src/electron/modem/electronserialpipe_hal.h b/hal/src/electron/modem/electronserialpipe_hal.h
@@ -96,6 +96,10 @@ class ElectronSerialPipe
     */
     void txIrqBuf(void);
 
+    /** resumes paused receiver (hardware flow control)
+    */
+    void rxResume();
+
 protected:
     //! start transmission helper
     void txStart(void);

diff --git a/hal/src/electron/modem/mdm_hal.cpp b/hal/src/electron/modem/mdm_hal.cpp
@@ -2251,6 +2251,7 @@ int MDMParser::_getLine(Pipe<char>* pipe, char* buf, int len)
             { "\r\n>",                  NULL,               TYPE_PROMPT     }, // SMS
             { "\n>",                    NULL,               TYPE_PROMPT     }, // File
             { "\r\nABORTED\r\n",        NULL,               TYPE_ABORTED    }, // Current command aborted
+            { "\r\n",                   "\r\n",             TYPE_UNKNOWN    }, // If all else fails, break up generic strings
         };
         for (int i = 0; i < (int)(sizeof(lutF)/sizeof(*lutF)); i ++) {
             pipe->set(unkn);
@@ -2305,5 +2306,7 @@ int MDMElectronSerial::_send(const void* buf, int len)
 
 int MDMElectronSerial::getLine(char* buffer, int length)
 {
-    return _getLine(&_pipeRx, buffer, length);
+    int ret = _getLine(&_pipeRx, buffer, length);
+    rxResume();
+    return ret;
 }