From 32c44e1fa921aebf8a5ef9f778534a30aab39313 Mon Sep 17 00:00:00 2001 From: George Stark Date: Thu, 25 Apr 2024 20:12:53 +0300 Subject: [PATCH] pwm: meson: Use mul_u64_u64_div_u64() for frequency calculating MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit While calculating frequency for the given period u64 numbers are multiplied before division what can lead to overflow in theory so use secure mul_u64_u64_div_u64() which handles overflow correctly. Fixes: 329db102a26d ("pwm: meson: make full use of common clock framework") Suggested-by: Uwe Kleine-König Signed-off-by: George Stark Link: https://lore.kernel.org/r/20240425171253.2752877-4-gnstark@salutedevices.com Signed-off-by: Uwe Kleine-König --- drivers/pwm/pwm-meson.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c index 4a652d500dfc..b2f97dfb01bb 100644 --- a/drivers/pwm/pwm-meson.c +++ b/drivers/pwm/pwm-meson.c @@ -176,7 +176,7 @@ static int meson_pwm_calc(struct pwm_chip *chip, struct pwm_device *pwm, dev_dbg(pwmchip_parent(chip), "fin_freq: %ld Hz\n", fin_freq); - cnt = div_u64(fin_freq * period, NSEC_PER_SEC); + cnt = mul_u64_u64_div_u64(fin_freq, period, NSEC_PER_SEC); if (cnt > 0xffff) { dev_err(pwmchip_parent(chip), "unable to get period cnt\n"); return -EINVAL; @@ -191,7 +191,7 @@ static int meson_pwm_calc(struct pwm_chip *chip, struct pwm_device *pwm, channel->hi = 0; channel->lo = cnt; } else { - duty_cnt = div_u64(fin_freq * duty, NSEC_PER_SEC); + duty_cnt = mul_u64_u64_div_u64(fin_freq, duty, NSEC_PER_SEC); dev_dbg(pwmchip_parent(chip), "duty=%llu duty_cnt=%u\n", duty, duty_cnt);