The value of NSEC_PER_SEC << PWM_DUTY_WIDTH doesn't fix within a 32 bit integer causing a build warning/error (and the value truncated): drivers/pwm/pwm-tegra.c: In function ‘tegra_pwm_config’: drivers/pwm/pwm-tegra.c:148:53: error: result of ‘1000000000 << 8’ requires 39 bits to represent, but ‘long int’ only has 32 bits [-Werror=shift-overflow=] 148 | required_clk_rate = DIV_ROUND_UP_ULL(NSEC_PER_SEC << PWM_DUTY_WIDTH, | ^~ Explicitly cast to a u64 to ensure the correct result. Fixes: cfcb68817fb3 ("pwm: tegra: Improve required rate calculation") Signed-off-by: Steven Price <steven.price@xxxxxxx> --- drivers/pwm/pwm-tegra.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pwm/pwm-tegra.c b/drivers/pwm/pwm-tegra.c index 6fc4b69a3ba7..249dc0193297 100644 --- a/drivers/pwm/pwm-tegra.c +++ b/drivers/pwm/pwm-tegra.c @@ -145,7 +145,7 @@ static int tegra_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, * source clock rate as required_clk_rate, PWM controller will * be able to configure the requested period. */ - required_clk_rate = DIV_ROUND_UP_ULL(NSEC_PER_SEC << PWM_DUTY_WIDTH, + required_clk_rate = DIV_ROUND_UP_ULL((u64)NSEC_PER_SEC << PWM_DUTY_WIDTH, period_ns); if (required_clk_rate > clk_round_rate(pc->clk, required_clk_rate)) -- 2.34.1