From 202dc359addab29451d3d18243c3d957da5392c8 Mon Sep 17 00:00:00 2001
From: Wayne Lin <wayne.lin@amd.com>
Date: Mon, 15 Apr 2024 14:04:00 +0800
Subject: [PATCH] drm/amd/display: Defer handling mst up request in resume
[Why]
Like commit ec5fa9fcdeca ("drm/amd/display: Adjust the MST resume flow"), we
want to avoid handling mst topology changes before restoring the old state.
If we enable DP_UP_REQ_EN before calling drm_atomic_helper_resume(), have
changce to handle CSN event first and fire hotplug event before restoring the
cached state.
[How]
Disable mst branch sending up request event before we restoring the cached state.
DP_UP_REQ_EN will be set later when we call drm_dp_mst_topology_mgr_resume().
Cc: Mario Limonciello <mario.limonciello@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Reviewed-by: Hersen Wu <hersenxs.wu@amd.com>
Signed-off-by: Wayne Lin <wayne.lin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 1 -
1 file changed, 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 c863f400024b4..ecf5752ef35f9 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -2429,7 +2429,6 @@ 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");
--
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