diff options
| -rw-r--r-- | drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 64 |
1 files changed, 38 insertions, 26 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 12eb1a91a4e9..242f98564261 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -4817,8 +4817,8 @@ static void convert_custom_brightness(const struct amdgpu_dm_backlight_caps *cap uint32_t *user_brightness) { u32 brightness = scale_input_to_fw(min, max, *user_brightness); - u8 prev_signal = 0, prev_lum = 0; - int i = 0; + u8 lower_signal, upper_signal, upper_lum, lower_lum, lum; + int left, right; if (amdgpu_dc_debug_mask & DC_DISABLE_CUSTOM_BRIGHTNESS_CURVE) return; @@ -4826,32 +4826,44 @@ static void convert_custom_brightness(const struct amdgpu_dm_backlight_caps *cap if (!caps->data_points) return; - /* choose start to run less interpolation steps */ - if (caps->luminance_data[caps->data_points/2].input_signal > brightness) - i = caps->data_points/2; - do { - u8 signal = caps->luminance_data[i].input_signal; - u8 lum = caps->luminance_data[i].luminance; + left = 0; + right = caps->data_points - 1; + while (left <= right) { + int mid = left + (right - left) / 2; + u8 signal = caps->luminance_data[mid].input_signal; - /* - * brightness == signal: luminance is percent numerator - * brightness < signal: interpolate between previous and current luminance numerator - * brightness > signal: find next data point - */ - if (brightness > signal) { - prev_signal = signal; - prev_lum = lum; - i++; - continue; + /* Exact match found */ + if (signal == brightness) { + lum = caps->luminance_data[mid].luminance; + goto scale; } - if (brightness < signal) - lum = prev_lum + DIV_ROUND_CLOSEST((lum - prev_lum) * - (brightness - prev_signal), - signal - prev_signal); - *user_brightness = scale_fw_to_input(min, max, - DIV_ROUND_CLOSEST(lum * brightness, 101)); - return; - } while (i < caps->data_points); + + if (signal < brightness) + left = mid + 1; + else + right = mid - 1; + } + + /* verify bound */ + if (left >= caps->data_points) + left = caps->data_points - 1; + + /* At this point, left > right */ + lower_signal = caps->luminance_data[right].input_signal; + upper_signal = caps->luminance_data[left].input_signal; + lower_lum = caps->luminance_data[right].luminance; + upper_lum = caps->luminance_data[left].luminance; + + /* interpolate */ + if (right == left || !lower_lum) + lum = upper_lum; + else + lum = lower_lum + DIV_ROUND_CLOSEST((upper_lum - lower_lum) * + (brightness - lower_signal), + upper_signal - lower_signal); +scale: + *user_brightness = scale_fw_to_input(min, max, + DIV_ROUND_CLOSEST(lum * brightness, 101)); } static u32 convert_brightness_from_user(const struct amdgpu_dm_backlight_caps *caps, |