2019-10-02 17:00:14

by Matthias Kaehlcke

Subject: [PATCH v2] backlight: pwm_bl: Don't assign levels table repeatedly

pwm_backlight_probe() re-assigns pb->levels for every brightness
level. This is not needed and was likely not intended, since
neither side of the assignment changes during the loop. Assign
the field only once.

Signed-off-by: Matthias Kaehlcke <[email protected]>
---

Changes in v2:
- removed curly braces from for loop

drivers/video/backlight/pwm_bl.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index 746eebc411df..05d3b3802658 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -564,18 +564,17 @@ static int pwm_backlight_probe(struct platform_device *pdev)
memset(&props, 0, sizeof(struct backlight_properties));

if (data->levels) {
+ pb->levels = data->levels;
+
/*
* For the DT case, only when brightness levels is defined
* data->levels is filled. For the non-DT case, data->levels
* can come from platform data, however is not usual.
*/
- for (i = 0; i <= data->max_brightness; i++) {
+ for (i = 0; i <= data->max_brightness; i++)
if (data->levels[i] > pb->scale)
pb->scale = data->levels[i];

- pb->levels = data->levels;
- }
-
if (pwm_backlight_is_linear(data))
props.scale = BACKLIGHT_SCALE_LINEAR;
else
--
2.23.0.444.g18eeb5a265-goog

2019-10-03 10:07:11

by Daniel Thompson

Subject: Re: [PATCH v2] backlight: pwm_bl: Don't assign levels table repeatedly

On Wed, Oct 02, 2019 at 09:56:01AM -0700, Matthias Kaehlcke wrote:
> pwm_backlight_probe() re-assigns pb->levels for every brightness
> level. This is not needed and was likely not intended, since
> neither side of the assignment changes during the loop. Assign
> the field only once.
>
> Signed-off-by: Matthias Kaehlcke <[email protected]>

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

> ---
>
> Changes in v2:
> - removed curly braces from for loop
>
> drivers/video/backlight/pwm_bl.c | 7 +++----
> 1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
> index 746eebc411df..05d3b3802658 100644
> --- a/drivers/video/backlight/pwm_bl.c
> +++ b/drivers/video/backlight/pwm_bl.c
> @@ -564,18 +564,17 @@ static int pwm_backlight_probe(struct platform_device *pdev)
> memset(&props, 0, sizeof(struct backlight_properties));
>
> if (data->levels) {
> + pb->levels = data->levels;
> +
> /*
> * For the DT case, only when brightness levels is defined
> * data->levels is filled. For the non-DT case, data->levels
> * can come from platform data, however is not usual.
> */
> - for (i = 0; i <= data->max_brightness; i++) {
> + for (i = 0; i <= data->max_brightness; i++)
> if (data->levels[i] > pb->scale)
> pb->scale = data->levels[i];
>
> - pb->levels = data->levels;
> - }
> -
> if (pwm_backlight_is_linear(data))
> props.scale = BACKLIGHT_SCALE_LINEAR;
> else
> --
> 2.23.0.444.g18eeb5a265-goog
>
> _______________________________________________
> dri-devel mailing list
> [email protected]
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

2019-10-16 12:42:11

by Lee Jones

Subject: Re: [PATCH v2] backlight: pwm_bl: Don't assign levels table repeatedly

On Wed, 02 Oct 2019, Matthias Kaehlcke wrote:

> pwm_backlight_probe() re-assigns pb->levels for every brightness
> level. This is not needed and was likely not intended, since
> neither side of the assignment changes during the loop. Assign
> the field only once.
>
> Signed-off-by: Matthias Kaehlcke <[email protected]>
> ---
>
> Changes in v2:
> - removed curly braces from for loop
>
> drivers/video/backlight/pwm_bl.c | 7 +++----
> 1 file changed, 3 insertions(+), 4 deletions(-)

Applied, thanks.

--
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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