The inherent defect of the AMDGPU driver about hotplug

[Aaron Chou]

About one month ago, I have asked a question about HDMI hotplug, the link is:

https://gitlab.freedesktop.org/drm/amd/-/issues/1135#note_492460

And I have put one patch to fix this, as follows:

 39 diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
 40 index f355d9a752d2..ee657db9a228 100644
 41 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
 42 +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
 43 @@ -973,7 +973,7 @@ amdgpu_connector_dvi_detect(struct
drm_connector *connector, bool force)
 44         const struct drm_encoder_helper_funcs *encoder_funcs;
 45         int r;
 46         enum drm_connector_status ret =
connector_status_disconnected;
 47 -       bool dret = false, broken_edid = false;
 48 +       bool dret = false, broken_edid = false, undefined_flag =
false;
 49
 50         if (!drm_kms_helper_is_poll_worker()) {
 51                 r = pm_runtime_get_sync(connector->dev->dev);
 52 @@ -988,7 +988,12 @@ amdgpu_connector_dvi_detect(struct
drm_connector *connector, bool force)
 53
 54         if (amdgpu_connector->ddc_bus)
 55                 dret = amdgpu_display_ddc_probe(amdgpu_connector,
false);
 56 -       if (dret) {
 57 +
 58 +       /* Check the HDMI HPD pin status again */
 59 +       if (!amdgpu_display_hpd_sense(adev,
amdgpu_connector->hpd.hpd))
 60 +               undefined_flag = true;
 61 +
 62 +       if (dret && !undefined_flag) {
 63                 amdgpu_connector->detected_by_load = false;
 64                 amdgpu_connector_free_edid(connector);
 65                 amdgpu_connector_get_edid(connector);

Maybe the fix is sloppy, so I write the another patch:

 16 diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
 17 index c770d73352a7..bb59ebc9a6c8 100644
 18 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
 19 +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
 20 @@ -991,6 +991,7 @@ amdgpu_connector_dvi_detect(struct
drm_connector *connector, bool force)
 21         if (amdgpu_connector->ddc_bus)
 22                 dret = amdgpu_display_ddc_probe(amdgpu_connector,
false);
 23         if (dret) {
 24 +               schedule_work(&adev->hotplug_work);
 25                 amdgpu_connector->detected_by_load = false;
 26                 amdgpu_connector_free_edid(connector);
 27                 amdgpu_connector_get_edid(connector);

Which is better, or neither？

--
Regards,
Aaron