From 24d3749c11d949972d8c22e75567dc90ff5482e7 Mon Sep 17 00:00:00 2001 From: Lo-an Chen Date: Thu, 14 Nov 2024 17:53:41 +0800 Subject: [PATCH] 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. Cc: Mario Limonciello Cc: Alex Deucher Cc: stable@vger.kernel.org Reviewed-by: Nicholas Kazlauskas Signed-off-by: Lo-an Chen Signed-off-by: Alex Hung Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/dc/dml2/display_mode_core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/amd/display/dc/dml2/display_mode_core.c b/drivers/gpu/drm/amd/display/dc/dml2/display_mode_core.c index d851c081e3768..8dabb1ac0b684 100644 --- a/drivers/gpu/drm/amd/display/dc/dml2/display_mode_core.c +++ b/drivers/gpu/drm/amd/display/dc/dml2/display_mode_core.c @@ -1222,6 +1222,7 @@ static dml_bool_t CalculatePrefetchSchedule(struct display_mode_lib_scratch_st * s->dst_y_prefetch_oto = s->Tvm_oto_lines + 2 * s->Tr0_oto_lines + s->Lsw_oto; s->dst_y_prefetch_equ = p->VStartup - (*p->TSetup + dml_max(p->TWait + p->TCalc, *p->Tdmdl)) / s->LineTime - (*p->DSTYAfterScaler + (dml_float_t) *p->DSTXAfterScaler / (dml_float_t)p->myPipe->HTotal); + s->dst_y_prefetch_equ = dml_min(s->dst_y_prefetch_equ, 63.75); // limit to the reg limit of U6.2 for DST_Y_PREFETCH #ifdef __DML_VBA_DEBUG__ dml_print("DML::%s: HTotal = %u\n", __func__, p->myPipe->HTotal);