The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 3b7c59754cc22760760a84ebddb8e0b1e8dd871b Mon Sep 17 00:00:00 2001
From: Mario Kleiner mario.kleiner.de@gmail.com Date: Thu, 9 Jan 2020 16:20:27 +0100 Subject: [PATCH] drm/amd/display: Reorder detect_edp_sink_caps before link settings read.
read_current_link_settings_on_detect() on eDP 1.4+ may use the edp_supported_link_rates table which is set up by detect_edp_sink_caps(), so that function needs to be called first.
Reviewed-by: Harry Wentland harry.wentland@amd.com Signed-off-by: Mario Kleiner mario.kleiner.de@gmail.com Cc: Martin Leung martin.leung@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org
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 62d8289abb4e..4619f94f0ac7 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c @@ -817,8 +817,8 @@ static bool dc_link_detect_helper(struct dc_link *link, }
case SIGNAL_TYPE_EDP: { - read_current_link_settings_on_detect(link); detect_edp_sink_caps(link); + read_current_link_settings_on_detect(link); sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C_OVER_AUX; sink_caps.signal = SIGNAL_TYPE_EDP; break;