diff options
| author | Anthony Koo <Anthony.Koo@amd.com> | 2019-01-30 17:05:38 +0100 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2019-02-19 21:58:26 +0100 |
| commit | c19bd82f8b33f6cf505df0ff5027d4679fedaa3e (patch) | |
| tree | f0c27ae5c3f98ee43d6bfff789dc306a740ce982 | |
| parent | drm/amd/display: remove screen flashes on seamless boot (diff) | |
| download | linux-c19bd82f8b33f6cf505df0ff5027d4679fedaa3e.tar.xz linux-c19bd82f8b33f6cf505df0ff5027d4679fedaa3e.zip | |
drm/amd/display: Increase precision for backlight curve
[Why]
We are currently losing precision when we convert from
16 bit --> 8 bit --> 16 bit.
[How]
We shouldn't down convert unnecessarily and lose precision.
Keep values at 16 bit and use directly.
Signed-off-by: Anthony Koo <Anthony.Koo@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
| -rw-r--r-- | drivers/gpu/drm/amd/display/modules/power/power_helpers.c | 23 |
1 files changed, 4 insertions, 19 deletions
diff --git a/drivers/gpu/drm/amd/display/modules/power/power_helpers.c b/drivers/gpu/drm/amd/display/modules/power/power_helpers.c index 3ba87b076287..038b88221c5f 100644 --- a/drivers/gpu/drm/amd/display/modules/power/power_helpers.c +++ b/drivers/gpu/drm/amd/display/modules/power/power_helpers.c @@ -165,18 +165,11 @@ struct iram_table_v_2_2 { }; #pragma pack(pop) -static uint16_t backlight_8_to_16(unsigned int backlight_8bit) -{ - return (uint16_t)(backlight_8bit * 0x101); -} - static void fill_backlight_transform_table(struct dmcu_iram_parameters params, struct iram_table_v_2 *table) { unsigned int i; unsigned int num_entries = NUM_BL_CURVE_SEGS; - unsigned int query_input_8bit; - unsigned int query_output_8bit; unsigned int lut_index; table->backlight_thresholds[0] = 0; @@ -194,16 +187,13 @@ static void fill_backlight_transform_table(struct dmcu_iram_parameters params, * format U4.10. */ for (i = 1; i+1 < num_entries; i++) { - query_input_8bit = DIV_ROUNDUP((i * 256), num_entries); - lut_index = (params.backlight_lut_array_size - 1) * i / (num_entries - 1); ASSERT(lut_index < params.backlight_lut_array_size); - query_output_8bit = params.backlight_lut_array[lut_index] >> 8; table->backlight_thresholds[i] = - backlight_8_to_16(query_input_8bit); + cpu_to_be16(DIV_ROUNDUP((i * 65536), num_entries)); table->backlight_offsets[i] = - backlight_8_to_16(query_output_8bit); + cpu_to_be16(params.backlight_lut_array[lut_index]); } } @@ -212,8 +202,6 @@ static void fill_backlight_transform_table_v_2_2(struct dmcu_iram_parameters par { unsigned int i; unsigned int num_entries = NUM_BL_CURVE_SEGS; - unsigned int query_input_8bit; - unsigned int query_output_8bit; unsigned int lut_index; table->backlight_thresholds[0] = 0; @@ -231,16 +219,13 @@ static void fill_backlight_transform_table_v_2_2(struct dmcu_iram_parameters par * format U4.10. */ for (i = 1; i+1 < num_entries; i++) { - query_input_8bit = DIV_ROUNDUP((i * 256), num_entries); - lut_index = (params.backlight_lut_array_size - 1) * i / (num_entries - 1); ASSERT(lut_index < params.backlight_lut_array_size); - query_output_8bit = params.backlight_lut_array[lut_index] >> 8; table->backlight_thresholds[i] = - backlight_8_to_16(query_input_8bit); + cpu_to_be16(DIV_ROUNDUP((i * 65536), num_entries)); table->backlight_offsets[i] = - backlight_8_to_16(query_output_8bit); + cpu_to_be16(params.backlight_lut_array[lut_index]); } } |