From: Linus Walleij Date: Tue, 26 Jan 2021 21:32:00 +0000 (+0100) Subject: backlight: ktd253: Bring up in a known state X-Git-Tag: v5.12-rc1~114^2~1 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=57e0d7b7f8663d0a3a5facc83c445ffc9802ad65;p=thirdparty%2Fkernel%2Flinux.git backlight: ktd253: Bring up in a known state The KTD253 backlight might already be on when the driver is probed: then we don't really know what the current ratio is and all light intensity settings will be off relative to what it was at boot. To fix this, bring up the backlight OFF then move it to the default backlight from there so we know the state. Signed-off-by: Linus Walleij Reviewed-by: Daniel Thompson Signed-off-by: Lee Jones --- diff --git a/drivers/video/backlight/ktd253-backlight.c b/drivers/video/backlight/ktd253-backlight.c index e3fee3f1f5828..d7b287cffd5cb 100644 --- a/drivers/video/backlight/ktd253-backlight.c +++ b/drivers/video/backlight/ktd253-backlight.c @@ -137,15 +137,7 @@ static int ktd253_backlight_probe(struct platform_device *pdev) brightness = max_brightness; } - if (brightness) - /* This will be the default ratio when the KTD253 is enabled */ - ktd253->ratio = KTD253_MAX_RATIO; - else - ktd253->ratio = 0; - - ktd253->gpiod = devm_gpiod_get(dev, "enable", - brightness ? GPIOD_OUT_HIGH : - GPIOD_OUT_LOW); + ktd253->gpiod = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW); if (IS_ERR(ktd253->gpiod)) { ret = PTR_ERR(ktd253->gpiod); if (ret != -EPROBE_DEFER) @@ -153,6 +145,8 @@ static int ktd253_backlight_probe(struct platform_device *pdev) return ret; } gpiod_set_consumer_name(ktd253->gpiod, dev_name(dev)); + /* Bring backlight to a known off state */ + msleep(KTD253_T_OFF_MS); bl = devm_backlight_device_register(dev, dev_name(dev), dev, ktd253, &ktd253_backlight_ops, NULL);