[PATCH 2/2] drm/panel: lg-sw43408: use the full DCS brightness range

[David Heidelberg via B4 Relay <devnull+david.ixit.cz@kernel.org>]

From: David Heidelberg <david@ixit.cz>

The vendor firmware panel configuration (XBL DisplayDxe panel XML)
declares DCSMaxBrightness 0x332 with a two-byte brightness command,
and the driver already sends two bytes via
mipi_dsi_dcs_set_display_brightness_large().

Capping max_brightness at 255 therefore limits the panel to ~31% of
its real brightness range. Use the firmware maximum.

Fixes: 069a6c0e94f9 ("drm: panel: Add LG sw43408 panel driver")
Signed-off-by: David Heidelberg <david@ixit.cz>
---
 drivers/gpu/drm/panel/panel-lg-sw43408.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-lg-sw43408.c b/drivers/gpu/drm/panel/panel-lg-sw43408.c
index 0bf8e08f10b9c..332b15b6a4c94 100644
--- a/drivers/gpu/drm/panel/panel-lg-sw43408.c
+++ b/drivers/gpu/drm/panel/panel-lg-sw43408.c
@@ -202,18 +202,18 @@ static const struct backlight_ops sw43408_backlight_ops = {
 	.update_status = sw43408_backlight_update_status,
 };
 
 static int sw43408_backlight_init(struct sw43408_panel *ctx)
 {
 	struct device *dev = &ctx->link->dev;
 	const struct backlight_properties props = {
 		.type = BACKLIGHT_PLATFORM,
-		.brightness = 255,
-		.max_brightness = 255,
+		.brightness = 256,
+		.max_brightness = 818,
 	};
 
 	ctx->base.backlight = devm_backlight_device_register(dev, dev_name(dev), dev,
 							     ctx->link,
 							     &sw43408_backlight_ops,
 							     &props);
 
 	if (IS_ERR(ctx->base.backlight))

-- 
2.55.0