diff --git a/drivers/pwm/pwm-tiehrpwm.c b/drivers/pwm/pwm-tiehrpwm.c
index caf00fe..d3c1dff 100644
--- a/drivers/pwm/pwm-tiehrpwm.c
+++ b/drivers/pwm/pwm-tiehrpwm.c
@@ -221,7 +221,7 @@
 	unsigned short ps_divval, tb_divval;
 	int i, cmp_reg;
 
-	if (period_ns < 0 || duty_ns < 0 || period_ns > NSEC_PER_SEC)
+	if (period_ns > NSEC_PER_SEC)
 		return -ERANGE;
 
 	c = pc->clk_rate;