diff options
| author | Anthony Koo <[email protected]> | 2019-08-29 10:49:12 -0400 |
|---|---|---|
| committer | Alex Deucher <[email protected]> | 2019-10-03 09:10:57 -0500 |
| commit | 2ad0cdf9e2e9e079af34af681863fa638f2ee212 (patch) | |
| tree | 0798667d3915b9f27fac3fabc8b99e90853455ee /drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | |
| parent | 799c5b9cb91ca759df65707d2820b5fe1ee5383c (diff) | |
drm/amd/display: set minimum abm backlight level
[Why]
A lot of the time, the backlight characteristic curve maps min backlight
to a non-zero value.
But there are cases where we want the curve to intersect at 0.
In this scenario even if OS never asks to set 0% backlight, the ABM
reduction can result in backlight being lowered close to 0.
This particularly can cause problems in some LED drivers, and in
general just looks like backlight is completely off.
[How]
Add default cap to disallow backlight from dropping below 1%
even after ABM reduction is applied.
Signed-off-by: Anthony Koo <[email protected]>
Reviewed-by: Aric Cyr <[email protected]>
Acked-by: Leo Li <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
Diffstat (limited to 'drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c')
| -rw-r--r-- | drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 5 |
1 files changed, 5 insertions, 0 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 d73afa0835aa..83579e0619dc 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -942,6 +942,11 @@ static int dm_late_init(void *handle) params.backlight_lut_array_size = 16; params.backlight_lut_array = linear_lut; + /* Min backlight level after ABM reduction, Don't allow below 1% + * 0xFFFF x 0.01 = 0x28F + */ + params.min_abm_backlight = 0x28F; + /* todo will enable for navi10 */ if (adev->asic_type <= CHIP_RAVEN) { ret = dmcu_load_iram(dmcu, params); |