[PATCH v2 1/2] drm/amd/display: Fix AMDGPU_MAX_BL_LEVEL value

[Mario Limonciello]

[Why]
commit 16dc8bc27c2aa ("drm/amd/display: Export full brightness range to
userspace") adjusted the brightness range to scale to larger values, but
missed updating AMDGPU_MAX_BL_LEVEL which is needed to make sure that
scaling works properly with custom brightness curves.

[How]
As the change for max brightness of 0xFFFF only applies to devices
supporting DC, use existing DC define MAX_BACKLIGHT_LEVEL.

Fixes: 16dc8bc27c2aa ("drm/amd/display: Export full brightness range to 
userspace")
Signed-off-by: Mario Limonciello <mario.limoncie...@amd.com>
---
v2:
 * Use DC define instead
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 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 a139da1c47af..77302caaf24a 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -4689,7 +4689,7 @@ static int amdgpu_dm_mode_config_init(struct 
amdgpu_device *adev)
 }
 
 #define AMDGPU_DM_DEFAULT_MIN_BACKLIGHT 12
-#define AMDGPU_DM_DEFAULT_MAX_BACKLIGHT 255
+#define AMDGPU_DM_DEFAULT_MAX_BACKLIGHT MAX_BACKLIGHT_LEVEL
 #define AMDGPU_DM_MIN_SPREAD ((AMDGPU_DM_DEFAULT_MAX_BACKLIGHT - 
AMDGPU_DM_DEFAULT_MIN_BACKLIGHT) / 2)
 #define AUX_BL_DEFAULT_TRANSITION_TIME_MS 50
 
@@ -4751,16 +4751,16 @@ static int get_brightness_range(const struct 
amdgpu_dm_backlight_caps *caps,
        return 1;
 }
 
-/* Rescale from [min..max] to [0..AMDGPU_MAX_BL_LEVEL] */
+/* Rescale from [min..max] to [0..MAX_BACKLIGHT_LEVEL] */
 static inline u32 scale_input_to_fw(int min, int max, u64 input)
 {
-       return DIV_ROUND_CLOSEST_ULL(input * AMDGPU_MAX_BL_LEVEL, max - min);
+       return DIV_ROUND_CLOSEST_ULL(input * MAX_BACKLIGHT_LEVEL, max - min);
 }
 
-/* Rescale from [0..AMDGPU_MAX_BL_LEVEL] to [min..max] */
+/* Rescale from [0..MAX_BACKLIGHT_LEVEL] to [min..max] */
 static inline u32 scale_fw_to_input(int min, int max, u64 input)
 {
-       return min + DIV_ROUND_CLOSEST_ULL(input * (max - min), 
AMDGPU_MAX_BL_LEVEL);
+       return min + DIV_ROUND_CLOSEST_ULL(input * (max - min), 
MAX_BACKLIGHT_LEVEL);
 }
 
 static void convert_custom_brightness(const struct amdgpu_dm_backlight_caps 
*caps,
@@ -4980,7 +4980,7 @@ amdgpu_dm_register_backlight_device(struct 
amdgpu_dm_connector *aconnector)
                drm_dbg(drm, "Backlight caps: min: %d, max: %d, ac %d, dc 
%d\n", min, max,
                        caps->ac_level, caps->dc_level);
        } else
-               props.brightness = props.max_brightness = AMDGPU_MAX_BL_LEVEL;
+               props.brightness = props.max_brightness = MAX_BACKLIGHT_LEVEL;
 
        if (caps->data_points && !(amdgpu_dc_debug_mask & 
DC_DISABLE_CUSTOM_BRIGHTNESS_CURVE))
                drm_info(drm, "Using custom brightness curve\n");
-- 
2.49.0