6.15-stable review patch. If anyone has any objections, please let me know.
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From: Mario Limonciello mario.limonciello@amd.com
[Why] When BIOS includes a lot of custom brightness data points, walking the entire list can be time consuming. This is most noticed when dragging a power slider. The "higher" values are "slower" to drag around.
[How] Move custom brightness calculation loop into a static function. Before starting the loop check the "half way" data point to see how it compares to the input. If greater than the half way data point use that as the starting point instead.
Reviewed-by: Alex Hung alex.hung@amd.com Signed-off-by: Mario Limonciello mario.limonciello@amd.com Signed-off-by: Roman Li roman.li@amd.com Tested-by: Daniel Wheeler daniel.wheeler@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com --- .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 53 ++++++++++++------- 1 file changed, 33 insertions(+), 20 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 e61166a8230b6..a9a719f051f90 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -4655,41 +4655,54 @@ static int get_brightness_range(const struct amdgpu_dm_backlight_caps *caps, return 1; }
-static u32 convert_brightness_from_user(const struct amdgpu_dm_backlight_caps *caps, - uint32_t brightness) +static void convert_custom_brightness(const struct amdgpu_dm_backlight_caps *caps, + uint32_t *brightness) { - unsigned int min, max; u8 prev_signal = 0, prev_lum = 0; + int i = 0;
- if (!get_brightness_range(caps, &min, &max)) - return brightness; - - for (int i = 0; i < caps->data_points; i++) { - u8 signal, lum; + if (amdgpu_dc_debug_mask & DC_DISABLE_CUSTOM_BRIGHTNESS_CURVE) + return;
- if (amdgpu_dc_debug_mask & DC_DISABLE_CUSTOM_BRIGHTNESS_CURVE) - break; + if (!caps->data_points) + return;
- signal = caps->luminance_data[i].input_signal; - lum = caps->luminance_data[i].luminance; + /* 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;
/* * brightness == signal: luminance is percent numerator * brightness < signal: interpolate between previous and current luminance numerator * brightness > signal: find next data point */ - if (brightness < signal) - lum = prev_lum + DIV_ROUND_CLOSEST((lum - prev_lum) * - (brightness - prev_signal), - signal - prev_signal); - else if (brightness > signal) { + if (*brightness > signal) { prev_signal = signal; prev_lum = lum; + i++; continue; } - brightness = DIV_ROUND_CLOSEST(lum * brightness, 101); - break; - } + if (*brightness < signal) + lum = prev_lum + DIV_ROUND_CLOSEST((lum - prev_lum) * + (*brightness - prev_signal), + signal - prev_signal); + *brightness = DIV_ROUND_CLOSEST(lum * *brightness, 101); + return; + } while (i < caps->data_points); +} + +static u32 convert_brightness_from_user(const struct amdgpu_dm_backlight_caps *caps, + uint32_t brightness) +{ + unsigned int min, max; + + if (!get_brightness_range(caps, &min, &max)) + return brightness; + + convert_custom_brightness(caps, &brightness);
// Rescale 0..255 to min..max return min + DIV_ROUND_CLOSEST((max - min) * brightness,