From a581ab50ceef2993d86a8786bd32e26356352eec Mon Sep 17 00:00:00 2001
From: Wenjing Liu <wenjing.liu@amd.com>
Date: Fri, 15 Oct 2021 12:48:41 -0400
Subject: drm/amd/display: fix register write sequence for LINK_SQUARE_PATTERN
Git-commit: edcf52caa985c010d0a6022190c8e3d3980a0223
Patch-mainline: v5.16-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
[why&how]
write LINK_SQUARE_PATTERN_num + 1 for square pulse pattern.
Specs requirement to write this register prior to write LINK_QUAL_LANEX_SET.
Acked-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Reviewed-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/dc/core/dc_link_dp.c | 8 ++++++++
drivers/gpu/drm/amd/display/dc/dc_dp_types.h | 3 +++
2 files changed, 11 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
index cc25ba0ec7db..cb7bf9148904 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
@@ -5329,6 +5329,14 @@ bool dc_link_dp_set_test_pattern(
return false;
if (link->dpcd_caps.dpcd_rev.raw >= DPCD_REV_12) {
+#if defined(CONFIG_DRM_AMD_DC_DCN)
+ if (test_pattern == DP_TEST_PATTERN_SQUARE_PULSE)
+ core_link_write_dpcd(link,
+ DP_LINK_SQUARE_PATTERN,
+ p_custom_pattern,
+ 1);
+
+#endif
/* tell receiver that we are sending qualification
* pattern DP 1.2 or later - DP receiver's link quality
* pattern is set using DPCD LINK_QUAL_LANEx_SET
diff --git a/drivers/gpu/drm/amd/display/dc/dc_dp_types.h b/drivers/gpu/drm/amd/display/dc/dc_dp_types.h
index bc87ea0adf94..e68e9a86a4d9 100644
--- a/drivers/gpu/drm/amd/display/dc/dc_dp_types.h
+++ b/drivers/gpu/drm/amd/display/dc/dc_dp_types.h
@@ -898,6 +898,9 @@ struct dpcd_usb4_dp_tunneling_info {
#ifndef DP_DFP_CAPABILITY_EXTENSION_SUPPORT
#define DP_DFP_CAPABILITY_EXTENSION_SUPPORT 0x0A3
#endif
+#ifndef DP_LINK_SQUARE_PATTERN
+#define DP_LINK_SQUARE_PATTERN 0x10F
+#endif
#ifndef DP_DSC_CONFIGURATION
#define DP_DSC_CONFIGURATION 0x161
#endif
--
2.38.1