From db31af12a5169f4ac26acec759c1d872eef26554 Mon Sep 17 00:00:00 2001
From: Jun Lei <Jun.Lei@amd.com>
Date: Mon, 3 Jun 2019 11:37:44 -0400
Subject: [PATCH] drm/amd/display: cap DCFCLK hardmin to 507 for NV10
[why]
Due to limitation in SMU/PPLIB, it is not possible to know Fmax @ Vmin for DCFCLK.
This causes issues at high display configurations where extra headroom of DCFCLK
can enable P-state switching
[how]
Use existing override logic. If override not defined, then force
min = 507
Signed-off-by: Jun Lei <Jun.Lei@amd.com>
Reviewed-by: Eric Yang <eric.yang2@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c
index d200bc3cec714..b949e202d6cb7 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c
@@ -2643,6 +2643,10 @@ static void update_bounding_box(struct dc *dc, struct _vcs_dpi_soc_bounding_box_
if (dc->bb_overrides.min_dcfclk_mhz > 0)
min_dcfclk = dc->bb_overrides.min_dcfclk_mhz;
+ else
+ // Accounting for SOC/DCF relationship, we can go as high as
+ // 506Mhz in Vmin. We need to code 507 since SMU will round down to 506.
+ min_dcfclk = 507;
for (i = 0; i < num_states; i++) {
int min_fclk_required_by_uclk;
--
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