From 05692bb02abd63959fde2108dbe80dd5082e4f89 Mon Sep 17 00:00:00 2001 From: Wenjing Liu Date: Fri, 24 Sep 2021 16:12:34 -0400 Subject: [PATCH] drm/amd/display: add DP2.0 debug option to set MST_EN for SST stream [why] Some DP2.0 RX requires us to set MST_EN even for SST configuration. We added this debug option so we can configure this temporary workaround for the RX. Reviewed-by: George Shen Acked-by: Agustin Gutierrez Sanchez Signed-off-by: Wenjing Liu Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/dc/core/dc_link.c | 7 ++++++- drivers/gpu/drm/amd/display/dc/dc.h | 1 + 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c index ca5dc3c168ec..fa11a2b094ba 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c @@ -1869,8 +1869,13 @@ static enum dc_status enable_link_dp(struct dc_state *state, do_fallback = true; #if defined(CONFIG_DRM_AMD_DC_DCN) + /* + * Temporary w/a to get DP2.0 link rates to work with SST. + * TODO DP2.0 - Workaround: Remove w/a if and when the issue is resolved. + */ if (dp_get_link_encoding_format(&link_settings) == DP_128b_132b_ENCODING && - pipe_ctx->stream->signal == SIGNAL_TYPE_DISPLAY_PORT) { + pipe_ctx->stream->signal == SIGNAL_TYPE_DISPLAY_PORT && + link->dc->debug.set_mst_en_for_sst) { dp_enable_mst_on_sink(link, true); } #endif diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h index dd995905b0cb..254b760ae91f 100644 --- a/drivers/gpu/drm/amd/display/dc/dc.h +++ b/drivers/gpu/drm/amd/display/dc/dc.h @@ -664,6 +664,7 @@ struct dc_debug_options { #if defined(CONFIG_DRM_AMD_DC_DCN) /* TODO - remove once tested */ bool legacy_dp2_lt; + bool set_mst_en_for_sst; #endif union mem_low_power_enable_options enable_mem_low_power; union root_clock_optimization_options root_clock_optimization; -- 2.34.1