[PATCH AUTOSEL 6.9 16/20] drm/amd/display: change dram_clock_latency to 34us for dcn35

From: Sasha Levin
Date: Sun Jun 30 2024 - 20:15:58 EST


From: Paul Hsieh <paul.hsieh@xxxxxxx>

[ Upstream commit 6071607bfefefc50a3907c0ba88878846960d29a ]

[Why & How]
Current DRAM setting would cause underflow on customer platform.
Modify dram_clock_change_latency_us from 11.72 to 34.0 us as per recommendation from HW team

Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx>
Acked-by: Zaeem Mohamed <zaeem.mohamed@xxxxxxx>
Signed-off-by: Paul Hsieh <paul.hsieh@xxxxxxx>
Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/amd/display/dc/dml/dcn35/dcn35_fpu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn35/dcn35_fpu.c b/drivers/gpu/drm/amd/display/dc/dml/dcn35/dcn35_fpu.c
index 53e40d3c48d4b..6716696df7719 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/dcn35/dcn35_fpu.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/dcn35/dcn35_fpu.c
@@ -177,7 +177,7 @@ struct _vcs_dpi_soc_bounding_box_st dcn3_5_soc = {
.urgent_latency_pixel_data_only_us = 4.0,
.urgent_latency_pixel_mixed_with_vm_data_us = 4.0,
.urgent_latency_vm_data_only_us = 4.0,
- .dram_clock_change_latency_us = 11.72,
+ .dram_clock_change_latency_us = 34.0,
.urgent_out_of_order_return_per_channel_pixel_only_bytes = 4096,
.urgent_out_of_order_return_per_channel_pixel_and_vm_bytes = 4096,
.urgent_out_of_order_return_per_channel_vm_only_bytes = 4096,
--
2.43.0