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| author | Fangzhi Zuo <jerry.zuo@amd.com> | 2026-08-27 13:12:46 -0400 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2026-09-10 12:02:27 -0400 |
| commit | 86420fe3093161971b4064e05be11ffff1df76aa (patch) | |
| tree | bae849df2703b75ba1c04d07c384c26274622cb2 | |
| parent | 1bb5d7034166c5324ba8f045f6dc110d6c727583 (diff) | |
| download | linux-next-86420fe3093161971b4064e05be11ffff1df76aa.tar.gz linux-next-86420fe3093161971b4064e05be11ffff1df76aa.zip | |
drm/amd/display: Exit IPS before connector detection on resume
[Why & How]
On resume, dm_resume() walks the connector list and, for each connector,
calls dc_link_detect_connection_type() at the top of the loop iteration
before the per-connector dc_exit_ips_for_hw_access() that sits in the
detection branch. There is no dc_exit_ips_for_hw_access() before the loop,
so the very first HW access relies on an earlier connector having already
taken the display out of IPS.
Commit d1d51519bc3b ("drm/amd/display: Skip eDP detection when no sink")
skips the eDP connector when no panel is present. On a DCN3.5 APU whose
eDP link has no sink, the eDP iteration - which used to bring the HW out
of IPS first - is now skipped, so a downstream DP connector becomes the
first one processed. Its initial DDC/AUX access then runs while the HW is
still idle, the AUX transfers time out (-ETIMEDOUT), and the EDID read
fails:
[drm:dm_helpers_read_local_edid [amdgpu]] *ERROR* EDID err: 2, on connector: DP-1
amdgpu: [drm] *ERROR* No EDID read.
Take the display out of IPS once before the detection loop so the first
connector processed no longer touches the AUX/DDC engine while the HW is
still in idle power state. This keeps the eDP-skip boot/resume
optimization while fixing the DP EDID read failure.
Fixes: d1d51519bc3b ("drm/amd/display: Skip eDP detection when no sink")
Reviewed-by: Roman Li <roman.li@amd.com>
Signed-off-by: Fangzhi Zuo <jerry.zuo@amd.com>
Signed-off-by: Ray Wu <ray.wu@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
| -rw-r--r-- | drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 4 |
1 files changed, 4 insertions, 0 deletions
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 4f4caa95f55a..73dd7c51c05c 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -2023,6 +2023,10 @@ static int dm_resume(struct amdgpu_ip_block *ip_block) /* On resume we need to rewrite the MSTM control bits to enable MST*/ s3_handle_mst(ddev, false); + /* Exit IPS before the detection loop's first AUX/DDC access. */ + scoped_guard(mutex, &dm->dc_lock) + dc_exit_ips_for_hw_access(dm->dc); + /* Do detection*/ drm_connector_list_iter_begin(ddev, &iter); drm_for_each_connector_iter(connector, &iter) { |