The note in c2adda27d202f ("video: backlight: Add of_find_backlight helper in backlight.c") says that gpio-backlight uses brightness as power state. Other backlight drivers do not, so limit this workaround to gpio-backlight.
This fixes the case where e.g. pwm-backlight can perfectly well be set to brightness 0 on boot in DT, which without this patch leads to the display brightness to be max instead of off.
Fixes: c2adda27d202f ("video: backlight: Add of_find_backlight helper in backlight.c") Signed-off-by: Marek Vasut marex@denx.de Cc: Daniel Thompson daniel.thompson@linaro.org Cc: Meghana Madhyastha meghana.madhyastha@gmail.com Cc: Noralf Trønnes noralf@tronnes.org Cc: Sean Paul seanpaul@chromium.org Cc: Thierry Reding treding@nvidia.com --- drivers/video/backlight/backlight.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c index 537fe1b376ad7..dfb66171dec41 100644 --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -676,6 +676,7 @@ EXPORT_SYMBOL(of_find_backlight_by_node); static struct backlight_device *of_find_backlight(struct device *dev) { struct backlight_device *bd = NULL; + bool is_gpio_backlight = false; struct device_node *np;
if (!dev) @@ -685,6 +686,8 @@ static struct backlight_device *of_find_backlight(struct device *dev) np = of_parse_phandle(dev->of_node, "backlight", 0); if (np) { bd = of_find_backlight_by_node(np); + is_gpio_backlight = + of_device_is_compatible(np, "gpio-backlight"); of_node_put(np); if (!bd) return ERR_PTR(-EPROBE_DEFER); @@ -692,7 +695,7 @@ static struct backlight_device *of_find_backlight(struct device *dev) * Note: gpio_backlight uses brightness as * power state during probe */ - if (!bd->props.brightness) + if (is_gpio_backlight && !bd->props.brightness) bd->props.brightness = bd->props.max_brightness; } }