Commit 563edf85 authored by Thomas Weißschuh's avatar Thomas Weißschuh Committed by Lee Jones
Browse files

backlight: Propagate errors from get_brightness() 



backlight.h documents "struct backlight_ops->get_brightness()" to return
a negative errno on failure.

So far these errors have not been handled in the backlight core.
This leads to negative values being exposed through sysfs although only
positive values are documented to be reported.

Signed-off-by: default avatarThomas Weißschuh <linux@weissschuh.net>
Reviewed-by: default avatarDaniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
parent 33a5471f

drivers/video/backlight/backlight.c

+17 −5
Original line number Diff line number Diff line
@@ -292,10 +292,13 @@ static ssize_t actual_brightness_show(struct device *dev, 
	struct backlight_device *bd = to_backlight_device(dev);



	mutex_lock(&bd->ops_lock);

	if (bd->ops && bd->ops->get_brightness)

		rc = sprintf(buf, "%d\n", bd->ops->get_brightness(bd));

	else

	if (bd->ops && bd->ops->get_brightness) {

		rc = bd->ops->get_brightness(bd);

		if (rc >= 0)

			rc = sprintf(buf, "%d\n", rc);

	} else {

		rc = sprintf(buf, "%d\n", bd->props.brightness);

	}

	mutex_unlock(&bd->ops_lock);



	return rc;
@@ -381,9 +384,18 @@ ATTRIBUTE_GROUPS(bl_device); 
void backlight_force_update(struct backlight_device *bd,

			    enum backlight_update_reason reason)

{

	int brightness;



	mutex_lock(&bd->ops_lock);

	if (bd->ops && bd->ops->get_brightness)

		bd->props.brightness = bd->ops->get_brightness(bd);

	if (bd->ops && bd->ops->get_brightness) {

		brightness = bd->ops->get_brightness(bd);

		if (brightness >= 0)

			bd->props.brightness = brightness;

		else

			dev_err(&bd->dev,

				"Could not update brightness from device: %pe\n",

				ERR_PTR(brightness));

	}

	mutex_unlock(&bd->ops_lock);

	backlight_generate_event(bd, reason);

}