From: Martin Tsai <martin.tsai@xxxxxxx> [ Upstream commit 616f5b65f1c02d3d6ae370644670d14c57de2fd8 ] [Why] The new implementation changed the behavior to allow process setMode to DAL when DAL returns empty mode query for unplugged display. This will trigger additional disable_link(). When unplug HDMI from MST dock, driver will update stream->signal to "Virtual". disable_link() will call disable_output() if the signal type is not DP and induce other displays on MST dock show black screen. [How] Don't need to process disable_output() if the signal type is virtual. Signed-off-by: Martin Tsai <martin.tsai@xxxxxxx> Reviewed-by: Charlene Liu <Charlene.Liu@xxxxxxx> Acked-by: Leo Li <sunpeng.li@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/gpu/drm/amd/display/dc/core/dc_link.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) 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 ca20b150afcc2..de1b61595ffbf 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c @@ -2169,8 +2169,10 @@ static void disable_link(struct dc_link *link, enum signal_type signal) dp_set_fec_ready(link, false); } #endif - } else - link->link_enc->funcs->disable_output(link->link_enc, signal); + } else { + if (signal != SIGNAL_TYPE_VIRTUAL) + link->link_enc->funcs->disable_output(link->link_enc, signal); + } if (signal == SIGNAL_TYPE_DISPLAY_PORT_MST) { /* MST disable link only when no stream use the link */ -- 2.20.1