drm/amd/display: Add delay to improve LTTPR UHBR interop

From Michael Strauss
479ccc2132171f7e711f8154408ec6106f6e1df3 in linux-6.6.y/6.6.46
10839ee6a977ed1f7d0f4deb29f2d7e5d1f2a9dd in mainline linux

diff --git a/sys/dev/pci/drm/amd/display/dc/link/hwss/link_hwss_hpo_fixed_vs_pe_retimer_dp.c b/sys/dev/pci/drm/amd/display/dc/link/hwss/link_hwss_hpo_fixed_vs_pe_retimer_dp.c
index 710f190..664a354 100644 (file)
--- a/sys/dev/pci/drm/amd/display/dc/link/hwss/link_hwss_hpo_fixed_vs_pe_retimer_dp.c
+++ b/sys/dev/pci/drm/amd/display/dc/link/hwss/link_hwss_hpo_fixed_vs_pe_retimer_dp.c
@@ -162,7 +162,12 @@ static void set_hpo_fixed_vs_pe_retimer_dp_link_test_pattern(struct dc_link *lin
                link_res->hpo_dp_link_enc->funcs->set_link_test_pattern(
                                link_res->hpo_dp_link_enc, tp_params);
        }
+
        link->dc->link_srv->dp_trace_source_sequence(link, DPCD_SOURCE_SEQ_AFTER_SET_SOURCE_PATTERN);
+
+       // Give retimer extra time to lock before updating DP_TRAINING_PATTERN_SET to TPS1
+       if (tp_params->dp_phy_pattern == DP_TEST_PATTERN_128b_132b_TPS1_TRAINING_MODE)
+               drm_msleep(30);
 }
 
 static void set_hpo_fixed_vs_pe_retimer_dp_lane_settings(struct dc_link *link,