2 files changed, 7 insertions, 1 deletions

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index 550443518891..21866ec69656 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -25,6 +25,7 @@ struct pwm_bl_data {
         struct pwm_device       *pwm;
         struct device           *dev;
         unsigned int            period;
+        unsigned int            lth_brightness;
         int                     (*notify)(struct device *,
                                           int brightness);
 };
@@ -48,7 +49,9 @@ static int pwm_backlight_update_status(struct backlight_device *bl)
                 pwm_config(pb->pwm, 0, pb->period);
                 pwm_disable(pb->pwm);
         } else {
-                pwm_config(pb->pwm, brightness * pb->period / max, pb->period);
+                brightness = pb->lth_brightness +
+                        (brightness * (pb->period - pb->lth_brightness) / max);
+                pwm_config(pb->pwm, brightness, pb->period);
                 pwm_enable(pb->pwm);
         }
         return 0;
@@ -92,6 +95,8 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 
         pb->period = data->pwm_period_ns;
         pb->notify = data->notify;
+        pb->lth_brightness = data->lth_brightness *
+                (data->pwm_period_ns / data->max_brightness);
         pb->dev = &pdev->dev;
 
         pb->pwm = pwm_request(data->pwm_id, "backlight");
diff --git a/include/linux/pwm_backlight.h b/include/linux/pwm_backlight.h
index 01b3d759f1fc..e031e1a486d9 100644
--- a/include/linux/pwm_backlight.h
+++ b/include/linux/pwm_backlight.h
@@ -8,6 +8,7 @@ struct platform_pwm_backlight_data {
         int pwm_id;
         unsigned int max_brightness;
         unsigned int dft_brightness;
+        unsigned int lth_brightness;
         unsigned int pwm_period_ns;
         int (*init)(struct device *dev);
         int (*notify)(struct device *dev, int brightness);