[PATCH] video: backlight: pwm: avoid integer overflow in duty cycle calculation

[Matthias Schiffer]

The intermediate value could overflow for large periods and levels.

Signed-off-by: Matthias Schiffer <matthias.schiffer at ew.tq-group.com>
---
 drivers/video/pwm_backlight.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/video/pwm_backlight.c b/drivers/video/pwm_backlight.c
index d7c096923b3..46c16a8f447 100644
--- a/drivers/video/pwm_backlight.c
+++ b/drivers/video/pwm_backlight.c
@@ -63,7 +63,7 @@ static int set_pwm(struct pwm_backlight_priv *priv)
 	int ret;
 
 	if (priv->period_ns) {
-		duty_cycle = priv->period_ns * (priv->cur_level - priv->min_level) /
+		duty_cycle = (u64)priv->period_ns * (priv->cur_level - priv->min_level) /
 			(priv->max_level - priv->min_level);
 		ret = pwm_set_config(priv->pwm, priv->channel, priv->period_ns,
 				     duty_cycle);
-- 
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