USCI fixes.

[tinyos-2.x.git] / tos / chips / msp430 / usci / Msp430UartP.nc

diff --git a/tos/chips/msp430/usci/Msp430UartP.nc b/tos/chips/msp430/usci/Msp430UartP.nc
index dcdc5b380d8370aa01507bf9783a5ececba13822..a4bec07698e521599d379e4c4634fb885e8d296a 100644 (file)
--- a/tos/chips/msp430/usci/Msp430UartP.nc
+++ b/tos/chips/msp430/usci/Msp430UartP.nc
@@ -146,14 +146,9 @@ implementation {
     atomic {
       if (m_sobuf || !buf || !len)
        return FAIL;
-      m_sobuf = buf;
-      m_solen = len;
-      while (!call Registers.getIfgTx());
+      m_sbuf = m_sobuf = buf;
+      m_slen = m_solen = len;
       call Registers.setIeTx();
-      call Registers.setTxbuf(*m_sobuf);
-      m_slen = m_solen - 1;
-      if (m_slen)
-       m_sbuf = m_sobuf + 1;
       return SUCCESS;
     }
   }
@@ -163,12 +158,13 @@ implementation {
     /* FIXME: this can cause an arbitrarily long ISR, if m_slen is large.
      * But depending on timing, we may always only write 1 byte.
      */
+    while (!call Registers.getIfgTx()); /* in case interleaved UB.send */
     while (m_slen && call Registers.getIfgTx()) {
       call Registers.setTxbuf(*m_sbuf);
       if (--m_slen)
        m_sbuf++;
     }
-    if (m_slen == 0 && m_sobuf) {
+    if (m_slen == 0) {
       call Registers.clrIeTx();
       m_sobuf = 0;
       signal UartStream.sendDone(m_sobuf, m_solen, SUCCESS);