diff options
| author | Xiubo Li <Li.Xiubo@freescale.com> | 2013-12-11 10:19:42 +0100 |
|---|---|---|
| committer | Bryan Wu <cooloney@gmail.com> | 2014-01-28 02:28:50 +0100 |
| commit | fc1aee038b609dc33067ca9dd477b16ea893cae0 (patch) | |
| tree | c098d278595f5efbdf7621969cf59d28aac6badf /drivers/leds | |
| parent | leds: leds-mc13783: Remove unneeded mc13xxx_{un}lock (diff) | |
| download | linux-fc1aee038b609dc33067ca9dd477b16ea893cae0.tar.xz linux-fc1aee038b609dc33067ca9dd477b16ea893cae0.zip | |
leds: leds-pwm: fix duty time overflow.
Overflow maybe occurs when calculates the duty time. For instance,
the period time is 990000000ns, and the max_brightness is 127, when
setting the brightness to 12, the duty value will be 25906026ns, but
it should be 93543307ns.
Signed-off-by: Bryan Wu <cooloney@gmail.com>
Diffstat (limited to 'drivers/leds')
| -rw-r--r-- | drivers/leds/leds-pwm.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c index b31d8e99c419..3fbd28e99b2c 100644 --- a/drivers/leds/leds-pwm.c +++ b/drivers/leds/leds-pwm.c @@ -66,9 +66,11 @@ static void led_pwm_set(struct led_classdev *led_cdev, struct led_pwm_data *led_dat = container_of(led_cdev, struct led_pwm_data, cdev); unsigned int max = led_dat->cdev.max_brightness; - unsigned int period = led_dat->period; + unsigned long long duty = led_dat->period; - led_dat->duty = brightness * period / max; + duty *= brightness; + do_div(duty, max); + led_dat->duty = duty; if (led_dat->can_sleep) schedule_work(&led_dat->work); |