diff --git a/common/tf_log.c b/common/tf_log.c
index 6da1e85..422959f 100644
--- a/common/tf_log.c
+++ b/common/tf_log.c
@@ -28,19 +28,21 @@
 	log_level = fmt[0];
 
 	/* Verify that log_level is one of LOG_MARKER_* macro defined in debug.h */
-	assert(log_level && log_level <= LOG_LEVEL_VERBOSE);
-	assert(log_level % 10 == 0);
+	assert((log_level > 0U) && (log_level <= LOG_LEVEL_VERBOSE));
+	assert((log_level % 10U) == 0U);
 
 	if (log_level > max_log_level)
 		return;
 
 	prefix_str = plat_log_get_prefix(log_level);
 
-	while (*prefix_str)
-		putchar(*prefix_str++);
+	while (*prefix_str != '\0') {
+		(void)putchar(*prefix_str);
+		prefix_str++;
+	}
 
 	va_start(args, fmt);
-	vprintf(fmt + 1, args);
+	(void)vprintf(fmt + 1, args);
 	va_end(args);
 }
 
@@ -52,10 +54,9 @@
 void tf_log_set_max_level(unsigned int log_level)
 {
 	assert(log_level <= LOG_LEVEL_VERBOSE);
-	assert((log_level % 10) == 0);
+	assert((log_level % 10U) == 0U);
 
 	/* Cap log_level to the compile time maximum. */
-	if (log_level < LOG_LEVEL)
+	if (log_level < (unsigned int)LOG_LEVEL)
 		max_log_level = log_level;
-
 }