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

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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: Jerry Zuo <Jerry.Zuo@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Jerry Zuo 2017-08-17 16:05:37 -04:00 committed by Alex Deucher
parent dff2721bd1
commit 3f1f74f436
2 changed files with 17 additions and 7 deletions
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16
drivers/gpu/drm/amd/display/dc/core/dc_link.c
View File

@ -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 */

8
drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
View File

@ -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