From: Steven Price <steven.price@xxxxxxx> [ Upstream commit dd1f1da4ada5d8ac774c2ebe97230637820b3323 ] 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> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> Reviewed-by: Jon Hunter <jonathanh@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 36cc1452cb7a..f3528c56e894 100644 --- a/drivers/pwm/pwm-tegra.c +++ b/drivers/pwm/pwm-tegra.c @@ -142,7 +142,7 @@ 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); err = clk_set_rate(pc->clk, required_clk_rate); -- 2.35.1