From e33697141bac18906345ea46533a240f1ad3cd21 Mon Sep 17 00:00:00 2001
From: Wayne Lin <Wayne.Lin@amd.com>
Date: Thu, 23 May 2024 12:18:07 +0800
Subject: [PATCH] drm/amd/display: Solve mst monitors blank out problem after
resume
[Why]
In dm resume, we firstly restore dc state and do the mst resume for topology
probing thereafter. If we change dpcd DP_MSTM_CTRL value after LT in mst reume,
it will cause light up problem on the hub.
[How]
Revert commit 202dc359adda ("drm/amd/display: Defer handling mst up request in resume").
And adjust the reason to trigger dc_link_detect by DETECT_REASON_RESUMEFROMS3S4.
Cc: stable@vger.kernel.org
Fixes: 202dc359adda ("drm/amd/display: Defer handling mst up request in resume")
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Reviewed-by: Fangzhi Zuo <jerry.zuo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 98cf523a629ef..29af22ddccc99 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -2583,6 +2583,7 @@ static void resume_mst_branch_status(struct drm_dp_mst_topology_mgr *mgr)
ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
DP_MST_EN |
+ DP_UP_REQ_EN |
DP_UPSTREAM_IS_SRC);
if (ret < 0) {
drm_dbg_kms(mgr->dev, "mst write failed - undocked during suspend?\n");
@@ -3186,7 +3187,7 @@ static int dm_resume(void *handle)
} else {
mutex_lock(&dm->dc_lock);
dc_exit_ips_for_hw_access(dm->dc);
- dc_link_detect(aconnector->dc_link, DETECT_REASON_HPD);
+ dc_link_detect(aconnector->dc_link, DETECT_REASON_RESUMEFROMS3S4);
mutex_unlock(&dm->dc_lock);
}
--
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