drm/amd/display: Connect DIG FE to its BE before link training starts

[why]
In SST mode no idle pattern will be generated after link training if
DIG FE is not connected to DIG BE.

Signed-off-by: Nikola Cornij <nikola.cornij@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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 1be4277..49f3d0f 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
@@ -1546,6 +1546,10 @@ static enum dc_status enable_link_dp(
        panel_mode = dp_get_panel_mode(link);
        dp_set_panel_mode(link, panel_mode);
 
+       /* We need to do this before the link training to ensure the idle pattern in SST
+        * mode will be sent right after the link training */
+       link->link_enc->funcs->connect_dig_be_to_fe(link->link_enc,
+                                                   pipe_ctx->stream_res.stream_enc->id, true);
        skip_video_pattern = true;
 
        if (link_settings.link_rate == LINK_RATE_LOW)