From: Samson Tam <Samson.Tam@xxxxxxx> [Why] Some of unit tests use large scaling ratio such that when we calculate optimal number of taps, max_taps is negative. Then in recent change, we changed max_taps to uint instead of int so now max_taps wraps and is positive. This change changed the behaviour from returning back false to return true and breaks unit test check [How] Add check to prevent max_taps from wrapping and set to 0 instead Signed-off-by: Samson Tam <Samson.Tam@xxxxxxx> Reviewed-by: Alvin Lee <alvin.lee2@xxxxxxx> --- drivers/gpu/drm/amd/display/dc/sspl/dc_spl.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/sspl/dc_spl.c b/drivers/gpu/drm/amd/display/dc/sspl/dc_spl.c index 047f05ab0181..ad77cef57ac7 100644 --- a/drivers/gpu/drm/amd/display/dc/sspl/dc_spl.c +++ b/drivers/gpu/drm/amd/display/dc/sspl/dc_spl.c @@ -1026,12 +1026,18 @@ static bool spl_get_optimal_number_of_taps( lb_config, &num_part_y, &num_part_c); /* MAX_V_TAPS = MIN (NUM_LINES - MAX(CEILING(V_RATIO,1)-2, 0), 8) */ if (spl_fixpt_ceil(spl_scratch->scl_data.ratios.vert) > 2) - max_taps_y = num_part_y - (spl_fixpt_ceil(spl_scratch->scl_data.ratios.vert) - 2); + if ((spl_fixpt_ceil(spl_scratch->scl_data.ratios.vert) - 2) > num_part_y) + max_taps_y = 0; + else + max_taps_y = num_part_y - (spl_fixpt_ceil(spl_scratch->scl_data.ratios.vert) - 2); else max_taps_y = num_part_y; if (spl_fixpt_ceil(spl_scratch->scl_data.ratios.vert_c) > 2) - max_taps_c = num_part_c - (spl_fixpt_ceil(spl_scratch->scl_data.ratios.vert_c) - 2); + if ((spl_fixpt_ceil(spl_scratch->scl_data.ratios.vert_c) - 2) > num_part_c) + max_taps_c = 0; + else + max_taps_c = num_part_c - (spl_fixpt_ceil(spl_scratch->scl_data.ratios.vert_c) - 2); else max_taps_c = num_part_c; -- 2.34.1
