Commit 3f1f74f4 authored by Jerry Zuo's avatar Jerry Zuo Committed by Alex Deucher
Browse files

drm/amd/display: Fix two MST not light up regressions 



1. Change 100104: Move verify link cap after read edid causes MST
   link_cap struct not being set. It leads to zero denominator
   pbn_per_slot value, leading to the crash at
   dal_fixed31_32_div(). Skip MST link training for now and will
   need to add MST specific link traning routine later.

2. Change 98822: Adding edp supports changes link setting
   condition from max_link to verified_link. It leads to MST is
   getting wrong link settings.
   e.g. LINK_SPREAD_05_DOWNSPREAD_30KHZ not set in MST case

Signed-off-by: default avatarJerry Zuo <Jerry.Zuo@amd.com>
Reviewed-by: default avatarTony Cheng <Tony.Cheng@amd.com>
Acked-by: default avatarHarry Wentland <Harry.Wentland@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent dff2721b

drivers/gpu/drm/amd/display/dc/core/dc_link.c

+9 −7
Original line number Diff line number Diff line
@@ -607,6 +607,12 @@ bool dc_link_detect(struct dc_link *link, bool boot) 
			if (link->type == dc_connection_mst_branch) {

				LINK_INFO("link=%d, mst branch is now Connected\n",

					link->link_index);

				/* Need to setup mst link_cap struct here

				 * otherwise dc_link_detect() will leave mst link_cap

				 * empty which leads to allocate_mst_payload() has "0"

				 * pbn_per_slot value leading to exception on dal_fixed31_32_div()

				 */

				link->verified_link_cap = link->reported_link_cap;

				return false;

			}
@@ -672,13 +678,9 @@ bool dc_link_detect(struct dc_link *link, bool boot) 
			 * TODO debug why Dell 2413 doesn't like

			 *  two link trainings

			 */

			if (is_mst_supported(link)) {

				link->verified_link_cap =

						link->reported_link_cap;

			} else {

				dp_hbr_verify_link_cap(link,

				    &link->reported_link_cap);

			}



			/* deal with non-mst cases */

			dp_hbr_verify_link_cap(link, &link->reported_link_cap);

		}



		/* HDMI-DVI Dongle */

drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c

+8 −0
Original line number Diff line number Diff line
@@ -1459,6 +1459,14 @@ void decide_link_settings(struct dc_stream_state *stream, 
		return;

	}



	/* MST doesn't perform link training for now

	 * TODO: add MST specific link training routine

	 */

	if (is_mst_supported(link)) {

		*link_setting = link->verified_link_cap;

		return;

	}



    /* search for the minimum link setting that:

     * 1. is supported according to the link training result

     * 2. could support the b/w requested by the timing