From 33bc89949b4366dff2dca30bc61ba1c0cbcd2ab2 Mon Sep 17 00:00:00 2001 From: TungYu Lu Date: Fri, 11 Apr 2025 10:41:48 +0800 Subject: drm/amd/display: Correct prefetch calculation [Why] The minimum value of the dst_y_prefetch_equ was not correct in prefetch calculation whice causes OPTC underflow. [How] Add the min operation of dst_y_prefetch_equ in prefetch calculation for legacy DML. Reviewed-by: Nicholas Kazlauskas Signed-off-by: TungYu Lu Signed-off-by: Zaeem Mohamed Tested-by: Mark Broadworth Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/gpu/drm/amd/display/dc/dml/dcn30') diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c b/drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c index f1fe49401bc0..8d24763938ea 100644 --- a/drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c +++ b/drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c @@ -1002,6 +1002,7 @@ static bool CalculatePrefetchSchedule( dst_y_prefetch_equ = VStartup - (Tsetup + dml_max(TWait + TCalc, *Tdmdl)) / LineTime - (*DSTYAfterScaler + *DSTXAfterScaler / myPipe->HTotal); + dst_y_prefetch_equ = dml_min(dst_y_prefetch_equ, 63.75); // limit to the reg limit of U6.2 for DST_Y_PREFETCH Lsw_oto = dml_max(PrefetchSourceLinesY, PrefetchSourceLinesC); Tsw_oto = Lsw_oto * LineTime; -- cgit v1.2.3