[PATCH 23/24] drm/amd/display: Fix default DC and AC levels

[Wayne Lin]

From: Mario Limonciello <mario.limonciello at amd.com>

[Why]
DC and AC levels are advertised in a percentage, not a luminance.

[How]
Scale DC and AC levels to supported values.

Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4221

Reviewed-by: Alex Hung <alex.hung at amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello at amd.com>
Signed-off-by: Wayne Lin <wayne.lin at amd.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

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 0d9a339d12eb..78816712afbb 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -4926,9 +4926,9 @@ amdgpu_dm_register_backlight_device(struct amdgpu_dm_connector *aconnector)
 	amdgpu_acpi_get_backlight_caps(&caps);
 	if (caps.caps_valid && get_brightness_range(&caps, &min, &max)) {
 		if (power_supply_is_system_supplied() > 0)
-			props.brightness = caps.ac_level;
+			props.brightness = (max - min) * DIV_ROUND_CLOSEST(caps.ac_level, 100);
 		else
-			props.brightness = caps.dc_level;
+			props.brightness = (max - min) * DIV_ROUND_CLOSEST(caps.dc_level, 100);
 		/* min is zero, so max needs to be adjusted */
 		props.max_brightness = max - min;
 		drm_dbg(drm, "Backlight caps: min: %d, max: %d, ac %d, dc %d\n", min, max,
-- 
2.43.0