diff options
| author | Aric Cyr <aric.cyr@amd.com> | 2019-03-01 10:24:37 -0500 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2019-03-20 23:39:48 -0500 |
| commit | 9070d18f89a8c7c839bc2dd3b1c6fbc8864c1be5 (patch) | |
| tree | 13939a2c92556de104677872fdf6200596caf017 /drivers/gpu/drm/amd/display/modules/freesync/freesync.c | |
| parent | 7fe538a4d64135d8f8e4aca8d0aedf266958025c (diff) | |
drm/amd/display: Add a hysteresis to BTR frame multiplier
[Why]
Flickering is observed on some displays when the number of inserted BTR
frames changes frequently.
[How]
Add in a margin of drift to prevent the inserted number of frames from
jumping around too frequently.
Signed-off-by: Aric Cyr <aric.cyr@amd.com>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu/drm/amd/display/modules/freesync/freesync.c')
| -rw-r--r-- | drivers/gpu/drm/amd/display/modules/freesync/freesync.c | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/drivers/gpu/drm/amd/display/modules/freesync/freesync.c b/drivers/gpu/drm/amd/display/modules/freesync/freesync.c index bfd27f10879e..5f493e9d6bbb 100644 --- a/drivers/gpu/drm/amd/display/modules/freesync/freesync.c +++ b/drivers/gpu/drm/amd/display/modules/freesync/freesync.c @@ -37,6 +37,8 @@ #define RENDER_TIMES_MAX_COUNT 10 /* Threshold to exit BTR (to avoid frequent enter-exits at the lower limit) */ #define BTR_EXIT_MARGIN 2000 +/* Threshold to change BTR multiplier (to avoid frequent changes) */ +#define BTR_DRIFT_MARGIN 2000 /*Threshold to exit fixed refresh rate*/ #define FIXED_REFRESH_EXIT_MARGIN_IN_HZ 4 /* Number of consecutive frames to check before entering/exiting fixed refresh*/ @@ -248,6 +250,7 @@ static void apply_below_the_range(struct core_freesync *core_freesync, unsigned int frames_to_insert = 0; unsigned int min_frame_duration_in_ns = 0; unsigned int max_render_time_in_us = in_out_vrr->max_duration_in_us; + unsigned int delta_from_mid_point_delta_in_us; min_frame_duration_in_ns = ((unsigned int) (div64_u64( (1000000000ULL * 1000000), @@ -318,10 +321,27 @@ static void apply_below_the_range(struct core_freesync *core_freesync, /* Choose number of frames to insert based on how close it * can get to the mid point of the variable range. */ - if (delta_from_mid_point_in_us_1 < delta_from_mid_point_in_us_2) + if (delta_from_mid_point_in_us_1 < delta_from_mid_point_in_us_2) { frames_to_insert = mid_point_frames_ceil; - else + delta_from_mid_point_delta_in_us = delta_from_mid_point_in_us_2 - + delta_from_mid_point_in_us_1; + } else { frames_to_insert = mid_point_frames_floor; + delta_from_mid_point_delta_in_us = delta_from_mid_point_in_us_1 - + delta_from_mid_point_in_us_2; + } + + /* Prefer current frame multiplier when BTR is enabled unless it drifts + * too far from the midpoint + */ + if (in_out_vrr->btr.frames_to_insert != 0 && + delta_from_mid_point_delta_in_us < BTR_DRIFT_MARGIN) { + if (((last_render_time_in_us / in_out_vrr->btr.frames_to_insert) < + in_out_vrr->max_duration_in_us) && + ((last_render_time_in_us / in_out_vrr->btr.frames_to_insert) > + in_out_vrr->min_duration_in_us)) + frames_to_insert = in_out_vrr->btr.frames_to_insert; + } /* Either we've calculated the number of frames to insert, * or we need to insert min duration frames |