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pwm_backlight: pass correct brightness to callback 

pwm_backlight_update_status calls the notify() and notify_after()
callbacks before and after applying the new PWM settings. However, if
brightness levels are used, the brightness value will be changed from
the index into the levels array to the PWM duty cycle length before
being passed to notify_after(), which results in inconsistent behavior.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
This commit is contained in:
Alexandre Courbot 2012-07-09 15:04:23 +09:00 committed by Thierry Reding
parent 2437b0d95c
commit 9fb978b12f
1 changed files with 8 additions and 4 deletions
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12
drivers/video/backlight/pwm_bl.c
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@ -54,14 +54,18 @@ static int pwm_backlight_update_status(struct backlight_device *bl)
pwm_config(pb->pwm, 0, pb->period);
pwm_disable(pb->pwm);
} else {
int duty_cycle;
if (pb->levels) {
brightness = pb->levels[brightness];
duty_cycle = pb->levels[brightness];
max = pb->levels[max];
} else {
duty_cycle = brightness;
}
brightness = pb->lth_brightness +
(brightness * (pb->period - pb->lth_brightness) / max);
pwm_config(pb->pwm, brightness, pb->period);
duty_cycle = pb->lth_brightness +
(duty_cycle * (pb->period - pb->lth_brightness) / max);
pwm_config(pb->pwm, duty_cycle, pb->period);
pwm_enable(pb->pwm);
}