From: Michael Strauss michael.strauss@amd.com
[ Upstream commit 10839ee6a977ed1f7d0f4deb29f2d7e5d1f2a9dd ]
[WHY] Avoid race condition which puts LTTPR into bad state during UHBR LT.
[HOW] Delay 30ms between starting UHBR TPS1 PHY output and sending TPS1 via DPCD.
Reviewed-by: Wenjing Liu wenjing.liu@amd.com Acked-by: Aurabindo Pillai aurabindo.pillai@amd.com Signed-off-by: Michael Strauss michael.strauss@amd.com Tested-by: Daniel Wheeler daniel.wheeler@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- .../dc/link/hwss/link_hwss_hpo_fixed_vs_pe_retimer_dp.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/dc/link/hwss/link_hwss_hpo_fixed_vs_pe_retimer_dp.c b/drivers/gpu/drm/amd/display/dc/link/hwss/link_hwss_hpo_fixed_vs_pe_retimer_dp.c index 3e6c7be7e2786..5302d2c9c7607 100644 --- a/drivers/gpu/drm/amd/display/dc/link/hwss/link_hwss_hpo_fixed_vs_pe_retimer_dp.c +++ b/drivers/gpu/drm/amd/display/dc/link/hwss/link_hwss_hpo_fixed_vs_pe_retimer_dp.c @@ -165,7 +165,12 @@ 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) + msleep(30); }
static void set_hpo_fixed_vs_pe_retimer_dp_lane_settings(struct dc_link *link,