2020-03-11 01:42:25

by Guru Das Srinagesh

Subject: [PATCH v8 11/12] backlight: pwm_bl: Use 64-bit division function

Since the PWM framework is switching struct pwm_state.period's datatype
to u64, prepare for this transition by using div_u64 to handle a 64-bit
dividend instead of a straight division operation.

Cc: Lee Jones <[email protected]>
Cc: Daniel Thompson <[email protected]>
Cc: Jingoo Han <[email protected]>
Cc: Bartlomiej Zolnierkiewicz <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]

Signed-off-by: Guru Das Srinagesh <[email protected]>
---
drivers/video/backlight/pwm_bl.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index efb4efc..3e5dbcf 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -625,7 +625,8 @@ static int pwm_backlight_probe(struct platform_device *pdev)
pb->scale = data->max_brightness;
}

- pb->lth_brightness = data->lth_brightness * (state.period / pb->scale);
+ pb->lth_brightness = data->lth_brightness * (div_u64(state.period,
+ pb->scale));

props.type = BACKLIGHT_RAW;
props.max_brightness = data->max_brightness;
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

2020-03-11 10:06:44

by Daniel Thompson

Subject: Re: [PATCH v8 11/12] backlight: pwm_bl: Use 64-bit division function

On Tue, Mar 10, 2020 at 06:41:20PM -0700, Guru Das Srinagesh wrote:
> Since the PWM framework is switching struct pwm_state.period's datatype
> to u64, prepare for this transition by using div_u64 to handle a 64-bit
> dividend instead of a straight division operation.
>
> Cc: Lee Jones <[email protected]>
> Cc: Daniel Thompson <[email protected]>
> Cc: Jingoo Han <[email protected]>
> Cc: Bartlomiej Zolnierkiewicz <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
>
> Signed-off-by: Guru Das Srinagesh <[email protected]>

Reviewed-by: Daniel Thompson <[email protected]>

> ---
> drivers/video/backlight/pwm_bl.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
> index efb4efc..3e5dbcf 100644
> --- a/drivers/video/backlight/pwm_bl.c
> +++ b/drivers/video/backlight/pwm_bl.c
> @@ -625,7 +625,8 @@ static int pwm_backlight_probe(struct platform_device *pdev)
> pb->scale = data->max_brightness;
> }
>
> - pb->lth_brightness = data->lth_brightness * (state.period / pb->scale);
> + pb->lth_brightness = data->lth_brightness * (div_u64(state.period,
> + pb->scale));
>
> props.type = BACKLIGHT_RAW;
> props.max_brightness = data->max_brightness;
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>