Silence signed/unsigned comparison warnings in GCC.

Why do the wait APIs take a signed integer if they are going to be
compared to unsigned quantities?

Author: adamgreen

libraries/mbed/common/wait_api.c

@@ -26,5 +26,5 @@ void wait_ms(int ms) {
 
 void wait_us(int us) {
     uint32_t start = us_ticker_read();
-    while ((us_ticker_read() - start) < us);
+    while ((us_ticker_read() - start) < (uint32_t)us);
 }

libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/ethernet_api.c

@@ -697,7 +697,7 @@ int ethernet_receive() {
     if(receive_idx == -1) {
       receive_idx = LPC_EMAC->RxConsumeIndex;
     } else {
-        while(!(rxstat[receive_idx].Info & RINFO_LAST_FLAG) && (receive_idx != LPC_EMAC->RxProduceIndex)) {
+        while(!(rxstat[receive_idx].Info & RINFO_LAST_FLAG) && ((uint32_t)receive_idx != LPC_EMAC->RxProduceIndex)) {
             receive_idx  = rinc(receive_idx, NUM_RX_FRAG);
         }
         unsigned int info =   rxstat[receive_idx].Info;
@@ -713,7 +713,7 @@ int ethernet_receive() {
         LPC_EMAC->RxConsumeIndex = receive_idx;
     }
 
-    if(receive_idx == LPC_EMAC->RxProduceIndex) {
+    if((uint32_t)receive_idx == LPC_EMAC->RxProduceIndex) {
         receive_idx = -1;
         return 0;
     }
@@ -762,7 +762,7 @@ int ethernet_read(char *data, int dlen) {
     void        *pdst, *psrc;
     int          doff = 0;
 
-    if(receive_idx == LPC_EMAC->RxProduceIndex || receive_idx == -1) {
+    if((uint32_t)receive_idx == LPC_EMAC->RxProduceIndex || receive_idx == -1) {
         return 0;
     }