Removing warnings from compilation

Marlin/src/HAL/HAL_LPC1768/u8g_com_HAL_LPC1768_ssd_hw_i2c.cpp

@@ -142,20 +142,26 @@ uint8_t u8g_com_HAL_LPC1768_ssd_hw_i2c_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_v
       //u8g->pin_list[U8G_PI_SET_A0] = 1;
       //if (u8g_com_arduino_ssd_start_sequence(u8g) == 0)
       //  return u8g_i2c_stop(), 0;
-      if (u8g_i2c_send_byte(arg_val) == 0)
+      if (u8g_i2c_send_byte(arg_val) == 0) {
-        return u8g_i2c_stop(), 0;
+        u8g_i2c_stop();
+        return 0;
+      }
       // u8g_i2c_stop();
       break;
 
     case U8G_COM_MSG_WRITE_SEQ: {
         //u8g->pin_list[U8G_PI_SET_A0] = 1;
-      if (u8g_com_ssd_I2C_start_sequence(u8g) == 0)
+        if (u8g_com_ssd_I2C_start_sequence(u8g) == 0) {
-        return u8g_i2c_stop(), 0;
+         u8g_i2c_stop();
+         return 0;
+        }
 
         register uint8_t *ptr = (uint8_t *)arg_ptr;
         while (arg_val > 0) {
-          if (u8g_i2c_send_byte(*ptr++) == 0)
+          if (u8g_i2c_send_byte(*ptr++) == 0) {
-            return u8g_i2c_stop(), 0;
+            u8g_i2c_stop();
+            return 0;
+          }
           arg_val--;
         }
       }
@@ -164,8 +170,10 @@ uint8_t u8g_com_HAL_LPC1768_ssd_hw_i2c_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_v
 
     case U8G_COM_MSG_WRITE_SEQ_P: {
         //u8g->pin_list[U8G_PI_SET_A0] = 1;
-        if (u8g_com_ssd_I2C_start_sequence(u8g) == 0)
+        if (u8g_com_ssd_I2C_start_sequence(u8g) == 0) {
-          return u8g_i2c_stop(), 0;
+          u8g_i2c_stop();
+          return 0;
+        }
 
         register uint8_t *ptr = (uint8_t *)arg_ptr;
         while (arg_val > 0) {

Marlin/src/HAL/HAL_LPC1768/u8g_com_HAL_LPC1768_st7920_hw_spi.cpp

@@ -79,7 +79,6 @@ void spiSend(const uint8_t* buf, size_t n);
 static uint8_t rs_last_state = 255;
 
 static void u8g_com_LPC1768_st7920_write_byte_hw_spi(uint8_t rs, uint8_t val) {
-  uint8_t i;
 
   if ( rs != rs_last_state) {  // time to send a command/data byte
     rs_last_state = rs;

Marlin/src/backtrace/unwarm_thumb.cpp

@@ -255,10 +255,9 @@ UnwResult UnwStartThumb(UnwState * const state) {
          * the switch clauses
          */
         uint8_t rn = instr & 0xF;
-        uint8_t rm = instr2 & 0xF;
         bool H = (instr2 & 0x10) ? true : false;
 
-        UnwPrintd5("TB%c [r%d,r%d%s]\n", H ? 'H' : 'B', rn, rm, H ? ",LSL #1" : "");
+        UnwPrintd5("TB%c [r%d,r%d%s]\n", H ? 'H' : 'B', rn, (instr2 & 0xF), H ? ",LSL #1" : "");
 
         // We are only interested if the RN is the PC. Let's choose the 1st destination
         if (rn == 15) {

Marlin/src/backtrace/unwarmbytab.cpp

@@ -185,7 +185,7 @@ static UnwResult UnwTabExecuteInstructions(const UnwindCallbacks *cb, UnwTabStat
       /* pop r4-r[4+nnn] or pop r4-r[4+nnn], r14*/
       vsp = ucb->vrs[13];
 
-      for (reg = 4; reg <= (instruction & 0x07) + 4; ++reg) {
+      for (reg = 4; reg <= uint32_t((instruction & 0x07) + 4); ++reg) {
         uint32_t v;
         if (!cb->readW(vsp,&v))
           return UNWIND_DREAD_W_FAIL;