diff --git a/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c b/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c
index 2d77f465f1ee..5fb6b0883e55 100644
--- a/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c
+++ b/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c
@@ -34,6 +34,9 @@
 #define	OPTARG_BALANCE_PERFORMANCE	(INT_MAX - 4)
 #define	OPTARG_PERFORMANCE		(INT_MAX - 5)
 
+/* Maximum HWP activity window duration in microseconds */
+#define HWP_WINDOW_MAX_USEC 1270000000U
+
 struct msr_hwp_cap {
 	unsigned char highest;
 	unsigned char guaranteed;
@@ -259,7 +262,7 @@ int parse_cmdline_hwp_desired(int i)
 	return i;
 }
 
-int parse_cmdline_hwp_window(int i)
+unsigned int parse_cmdline_hwp_window(unsigned int i)
 {
 	unsigned int exponent;
 
@@ -273,13 +276,13 @@ int parse_cmdline_hwp_window(int i)
 	case OPTARG_PERFORMANCE:
 		return 0;
 	}
-	if (i < 0 || i > 1270000000) {
-		fprintf(stderr, "--hwp-window: 0 for auto; 1 - 1270000000 usec for window duration\n");
+	if (i > HWP_WINDOW_MAX_USEC) {
+		fprintf(stderr, "--hwp-window: 0 for auto; 1 - %u usec for window duration\n", HWP_WINDOW_MAX_USEC);
 		usage();
 	}
 	for (exponent = 0;; ++exponent) {
 		if (debug)
-			printf("%d 10^%d\n", i, exponent);
+			printf("%u 10^%d\n", i, exponent);
 
 		if (i <= 127)
 			break;
@@ -287,7 +290,7 @@ int parse_cmdline_hwp_window(int i)
 		i = i / 10;
 	}
 	if (debug)
-		fprintf(stderr, "%d*10^%d: 0x%x\n", i, exponent, (exponent << 7) | i);
+		fprintf(stderr, "%u*10^%d: 0x%x\n", i, exponent, (exponent << 7) | i);
 
 	return (exponent << 7) | i;
 }