[PATCH AUTOSEL 4.18 100/113] drm/amd/display: Read back max backlight value at boot

From: David Francis <redacted>

[ Upstream commit 53a53f8687faf492df2644d8c18ff0217fc18730 ]

[Why]
If there is no program explicitly setting the backlight
brightness (for example, during a minimal install of linux), the
hardware defaults to maximum brightness but the backlight_device
defaults to 0 value.  Thus, settings displays the wrong brightness
value.

[How]
When creating the backlight device, set brightness to max

Signed-off-by: David Francis <redacted>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Acked-by: Bhawanpreet Lakha <redacted>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <redacted>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 770c6b24be0b..a1d90331a903 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -1334,6 +1334,7 @@ amdgpu_dm_register_backlight_device(struct amdgpu_display_manager *dm)
 	struct backlight_properties props = { 0 };
 
 	props.max_brightness = AMDGPU_MAX_BL_LEVEL;
+	props.brightness = AMDGPU_MAX_BL_LEVEL;
 	props.type = BACKLIGHT_RAW;
 
 	snprintf(bl_name, sizeof(bl_name), "amdgpu_bl%d",

-- 
2.17.1