* [PATCH] video: backlight: pwm: avoid integer overflow in duty cycle calculation
@ 2023-06-30 12:30 Matthias Schiffer
2023-07-03 13:30 ` Simon Glass
2023-07-17 15:22 ` Anatolij Gustschin
0 siblings, 2 replies; 3+ messages in thread
From: Matthias Schiffer @ 2023-06-30 12:30 UTC (permalink / raw)
To: u-boot, Anatolij Gustschin; +Cc: u-boot, Matthias Schiffer
The intermediate value could overflow for large periods and levels.
Signed-off-by: Matthias Schiffer <matthias.schiffer@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);
--
TQ-Systems GmbH | Mühlstraße 2, Gut Delling | 82229 Seefeld, Germany
Amtsgericht München, HRB 105018
Geschäftsführer: Detlef Schneider, Rüdiger Stahl, Stefan Schneider
https://www.tq-group.com/
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] video: backlight: pwm: avoid integer overflow in duty cycle calculation
2023-06-30 12:30 [PATCH] video: backlight: pwm: avoid integer overflow in duty cycle calculation Matthias Schiffer
@ 2023-07-03 13:30 ` Simon Glass
2023-07-17 15:22 ` Anatolij Gustschin
1 sibling, 0 replies; 3+ messages in thread
From: Simon Glass @ 2023-07-03 13:30 UTC (permalink / raw)
To: Matthias Schiffer; +Cc: u-boot, Anatolij Gustschin, u-boot
On Fri, 30 Jun 2023 at 13:38, Matthias Schiffer
<matthias.schiffer@ew.tq-group.com> wrote:
>
> The intermediate value could overflow for large periods and levels.
>
> Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
> ---
> drivers/video/pwm_backlight.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
Reviewed-by: Simon Glass <sjg@chromium.org>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] video: backlight: pwm: avoid integer overflow in duty cycle calculation
2023-06-30 12:30 [PATCH] video: backlight: pwm: avoid integer overflow in duty cycle calculation Matthias Schiffer
2023-07-03 13:30 ` Simon Glass
@ 2023-07-17 15:22 ` Anatolij Gustschin
1 sibling, 0 replies; 3+ messages in thread
From: Anatolij Gustschin @ 2023-07-17 15:22 UTC (permalink / raw)
To: Matthias Schiffer; +Cc: u-boot, u-boot
On Fri, 30 Jun 2023 14:30:07 +0200
Matthias Schiffer matthias.schiffer@ew.tq-group.com wrote:
> The intermediate value could overflow for large periods and levels.
>
> Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
> ---
applied to u-boot-video/master, thanks!
--
Anatolij
^ permalink raw reply [flat|nested] 3+ messages in thread
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2023-06-30 12:30 [PATCH] video: backlight: pwm: avoid integer overflow in duty cycle calculation Matthias Schiffer
2023-07-03 13:30 ` Simon Glass
2023-07-17 15:22 ` Anatolij Gustschin
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