[PATCH 5.4 029/111] drm/amd/display: Revert dram_clock_change_latency for DCN2.1

From: Greg Kroah-Hartman
Date: Mon Mar 29 2021 - 04:20:07 EST


From: Sung Lee <sung.lee@xxxxxxx>

[ Upstream commit b0075d114c33580f5c9fa9cee8e13d06db41471b ]

[WHY & HOW]
Using values provided by DF for latency may cause hangs in
multi display configurations. Revert change to previous value.

Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Sung Lee <sung.lee@xxxxxxx>
Reviewed-by: Haonan Wang <Haonan.Wang2@xxxxxxx>
Acked-by: Eryk Brol <eryk.brol@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c b/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c
index f63cbbee7b33..11a4c4029a90 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c
@@ -257,7 +257,7 @@ struct _vcs_dpi_soc_bounding_box_st dcn2_1_soc = {
.num_banks = 8,
.num_chans = 4,
.vmm_page_size_bytes = 4096,
- .dram_clock_change_latency_us = 11.72,
+ .dram_clock_change_latency_us = 23.84,
.return_bus_width_bytes = 64,
.dispclk_dppclk_vco_speed_mhz = 3600,
.xfc_bus_transport_time_us = 4,
--
2.30.1