From 33915fdf08e158bc01f1b20952a265f113f057df Mon Sep 17 00:00:00 2001
From: George Shen <george.shen@amd.com>
Date: Wed, 14 Jun 2023 17:53:16 -0400
Subject: drm/amd/display: Update 128b/132b downspread factor to 0.3%
Git-commit: b97089b88c7f8359a772cc2a31e0a87d9441243a
Patch-mainline: v6.6-rc1
References: jsc#PED-3527 jsc#PED-5475 jsc#PED-6068 jsc#PED-6070 jsc#PED-6116 jsc#PED-6120 jsc#PED-5065 jsc#PED-5477 jsc#PED-5511 jsc#PED-6041 jsc#PED-6069 jsc#PED-6071
[Why]
Updating downspread factor to 0.3% to add additional margin to account
for potential link rate deviations (up to 300ppm as per the DP spec).
Reviewed-by: Wenjing Liu <wenjing.liu@amd.com>
Acked-by: Alan Liu <haoping.liu@amd.com>
Signed-off-by: George Shen <george.shen@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/amd/display/include/link_service_types.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/include/link_service_types.h b/drivers/gpu/drm/amd/display/include/link_service_types.h
index cd870af5fd25..1b8ab20f1715 100644
--- a/drivers/gpu/drm/amd/display/include/link_service_types.h
+++ b/drivers/gpu/drm/amd/display/include/link_service_types.h
@@ -53,7 +53,7 @@ enum {
BITS_PER_DP_BYTE = 10,
DATA_EFFICIENCY_8b_10b_x10000 = 8000, /* 80% data efficiency */
DATA_EFFICIENCY_8b_10b_FEC_EFFICIENCY_x100 = 97, /* 97% data efficiency when FEC is enabled */
- DATA_EFFICIENCY_128b_132b_x10000 = 9646, /* 96.71% data efficiency x 99.75% downspread factor */
+ DATA_EFFICIENCY_128b_132b_x10000 = 9641, /* 96.71% data efficiency x 99.7% downspread factor */
};
enum lttpr_mode {
--
2.43.0