Re: [PATCH 07/11] drm/amd/display: Attach privacy screen to DRM connector

["Limonciello, Mario" <Mario.Limonciello@amd.com>]

On 8/18/25 4:16 PM, Alex Deucher wrote:
> On Wed, Aug 13, 2025 at 7:33 PM Alex Hung <alex.hung@amd.com> wrote:
>>
>> From: Mario Limonciello <mario.limonciello@amd.com>
>>
>> [WHY]
>> If a system has a privacy screen advertised by a driver it should
>> be included in the DRM connector for the eDP panel.
>>
>> [HOW]
>> Detect statically declared privacy screens when creating eDP connector
>> and attach privacy screen DRM properties.
>>
>> Reviewed-by: Harry Wentland <harry.wentland@amd.com>
>> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
>> Signed-off-by: Alex Hung <alex.hung@amd.com>
>> ---
>>   .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 25 ++++++++++++++++++-
>>   1 file changed, 24 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 e8cfae2bd2ae..176f420effd9 100644
>> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> @@ -80,6 +80,7 @@
>>   #include <linux/component.h>
>>   #include <linux/sort.h>
>>
>> +#include <drm/drm_privacy_screen_consumer.h>
>>   #include <drm/display/drm_dp_mst_helper.h>
>>   #include <drm/display/drm_hdmi_helper.h>
>>   #include <drm/drm_atomic.h>
>> @@ -7846,6 +7847,14 @@ amdgpu_dm_connector_atomic_check(struct drm_connector *conn,
>>          if (!crtc)
>>                  return 0;
>>
>> +       if (new_con_state->privacy_screen_sw_state != old_con_state->privacy_screen_sw_state) {
>> +               new_crtc_state = drm_atomic_get_crtc_state(state, crtc);
>> +               if (IS_ERR(new_crtc_state))
>> +                       return PTR_ERR(new_crtc_state);
>> +
>> +               new_crtc_state->mode_changed = true;
>> +       }
>> +
>>          if (new_con_state->colorspace != old_con_state->colorspace) {
>>                  new_crtc_state = drm_atomic_get_crtc_state(state, crtc);
>>                  if (IS_ERR(new_crtc_state))
>> @@ -8541,6 +8550,18 @@ void amdgpu_dm_connector_init_helper(struct amdgpu_display_manager *dm,
>>                  if (adev->dm.hdcp_workqueue)
>>                          drm_connector_attach_content_protection_property(&aconnector->base, true);
>>          }
>> +
>> +       if (connector_type == DRM_MODE_CONNECTOR_eDP) {
> 
> Do the privacy screens exist on any old laptops with LVDS?  If so, we
> should add DRM_MODE_CONNECTOR_LVDS here as well.
> 
> Alex

At least for AMD laptops I don't think so.  They're for newer designs 
that would solely be connected eDP.

> 
>> +               struct drm_privacy_screen *privacy_screen;
>> +
>> +               privacy_screen = drm_privacy_screen_get(adev_to_drm(adev)->dev, NULL);
>> +               if (!IS_ERR(privacy_screen)) {
>> +                       drm_connector_attach_privacy_screen_provider(&aconnector->base,
>> +                                                                    privacy_screen);
>> +               } else if (PTR_ERR(privacy_screen) != -ENODEV) {
>> +                       drm_warn(adev_to_drm(adev), "Error getting privacy-screen\n");
>> +               }
>> +       }
>>   }
>>
>>   static int amdgpu_dm_i2c_xfer(struct i2c_adapter *i2c_adap,
>> @@ -10265,7 +10286,7 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
>>          unsigned long flags;
>>          bool wait_for_vblank = true;
>>          struct drm_connector *connector;
>> -       struct drm_connector_state *old_con_state, *new_con_state;
>> +       struct drm_connector_state *old_con_state = NULL, *new_con_state = NULL;
>>          struct dm_crtc_state *dm_old_crtc_state, *dm_new_crtc_state;
>>          int crtc_disable_count = 0;
>>
>> @@ -10383,6 +10404,8 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
>>                                              &stream_update);
>>                  mutex_unlock(&dm->dc_lock);
>>                  kfree(dummy_updates);
>> +
>> +               drm_connector_update_privacy_screen(new_con_state);
>>          }
>>
>>          /**
>> --
>> 2.43.0
>>