From: Dan White <dan@whiteaudio.com>
Date: Sun, 1 Feb 2015 19:27:55 +0000 (-0600)
Subject: Workaround unused-but-set-variable warning.
X-Git-Tag: cheetah~7
X-Git-Url: http://git.whiteaudio.com/gitweb/?a=commitdiff_plain;h=d8af276be32af24f2797ba121d958cfd7156c1d4;p=430.git

Workaround unused-but-set-variable warning.

The UART status register must be read to clear the flags and enable operation.
Previously, it was read into a dummy variable which triggered the warning.
Attempts to suppress the warning didn't work for some reason, but the
statement "UART0_SR;" is sufficient to emit assembly to read the register.

I don't trust this to always work, so there is a comment with the purpose
of the line.
---

diff --git a/msp4th/main.c b/msp4th/main.c
index e14e849..c389cbd 100644
--- a/msp4th/main.c
+++ b/msp4th/main.c
@@ -89,7 +89,6 @@ static void __inline__ eint(void){
 
 static __inline__ void init_uart(void)
 {
-    int16_t tmp;
     // chip setup for UART0 use
     PAPER = 0x0030;
     PAOUT = 0x0000;
@@ -99,7 +98,9 @@ static __inline__ void init_uart(void)
     UART0_CR = UARTEn;
 
     // a read clears the register -- ready for TX/RX
-    tmp = UART0_SR;
+    // NOTE: make sure the ASM actually reads this register
+    //       and isn't "optimized" out.  So far, no problems...
+    UART0_SR;
 }