drm/amd/display: Fix possible underflow for displays with large vblank

[Why]
Underflow observed when using a display with a large vblank region
and low refresh rate

[How]
Simplify calculation of vblank_nom

Increase value for VBlankNomDefaultUS to 800us

Fixed a null pointer from previous commit of this change

Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Daniel Miess <daniel.miess@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Daniel Miess 2023-05-11 10:51:27 -04:00 committed by Alex Deucher
parent c02b04633c
commit de231189e7
1 changed files with 7 additions and 12 deletions

View File

@ -33,7 +33,7 @@
#include "dml/display_mode_vba.h"
struct _vcs_dpi_ip_params_st dcn3_14_ip = {
.VBlankNomDefaultUS = 668,
.VBlankNomDefaultUS = 800,
.gpuvm_enable = 1,
.gpuvm_max_page_table_levels = 1,
.hostvm_enable = 1,
@ -286,7 +286,7 @@ int dcn314_populate_dml_pipes_from_context_fpu(struct dc *dc, struct dc_state *c
struct resource_context *res_ctx = &context->res_ctx;
struct pipe_ctx *pipe;
bool upscaled = false;
bool isFreesyncVideo = false;
const unsigned int max_allowed_vblank_nom = 1023;
dc_assert_fp_enabled();
@ -300,16 +300,11 @@ int dcn314_populate_dml_pipes_from_context_fpu(struct dc *dc, struct dc_state *c
pipe = &res_ctx->pipe_ctx[i];
timing = &pipe->stream->timing;
isFreesyncVideo = pipe->stream->adjust.v_total_max == pipe->stream->adjust.v_total_min;
isFreesyncVideo = isFreesyncVideo && pipe->stream->adjust.v_total_min > timing->v_total;
if (!isFreesyncVideo) {
pipes[pipe_cnt].pipe.dest.vblank_nom =
dcn3_14_ip.VBlankNomDefaultUS / (timing->h_total / (timing->pix_clk_100hz / 10000.0));
} else {
pipes[pipe_cnt].pipe.dest.vtotal = pipe->stream->adjust.v_total_min;
pipes[pipe_cnt].pipe.dest.vblank_nom = timing->v_total - pipes[pipe_cnt].pipe.dest.vactive;
}
pipes[pipe_cnt].pipe.dest.vtotal = pipe->stream->adjust.v_total_min;
pipes[pipe_cnt].pipe.dest.vblank_nom = timing->v_total - pipes[pipe_cnt].pipe.dest.vactive;
pipes[pipe_cnt].pipe.dest.vblank_nom = min(pipes[pipe_cnt].pipe.dest.vblank_nom, dcn3_14_ip.VBlankNomDefaultUS);
pipes[pipe_cnt].pipe.dest.vblank_nom = max(pipes[pipe_cnt].pipe.dest.vblank_nom, timing->v_sync_width);
pipes[pipe_cnt].pipe.dest.vblank_nom = min(pipes[pipe_cnt].pipe.dest.vblank_nom, max_allowed_vblank_nom);
if (pipe->plane_state &&
(pipe->plane_state->src_rect.height < pipe->plane_state->dst_rect.height ||